It all begins on a dark stretch of American highway near Spoke City. Laid back jazz plays on the radio of a red convertible as a young man hums along, and then he switches stations to something rather more twee which makes me think of 1950s housewives dusting with big grins on their shiny faces. There are a lot of shots of the convertible's headlights on the dark road ahead. Next we're shown a dodgy looking, black-haired man lurking on the edge of the road. He's wearing a dark grey trenchcoat, so we already know he's bad news and possible eeeevil (sic) along with it. Actually, he looks like he could be Ned Cook's evil twin. The driver pulls over and greets the trenchcoat man (hereafter known as 'Trenchcoat' since he's never really named or identified) with a rather flirtatious, "Hi there". Trenchcoat asks if the driver is going where he's going, and the driver says "sure, hop in". As he sits down, Trenchcoat waffles about needing to get a doctor for his sick wife, and claims that his car battery had died. Sure it did. And that's your natural hair colour, too. The convertible drives on.

Trenchcoat reckons he was lucky to find the driver and asks if he's married. The driver says he is, it's actually his third wedding anniversary – there's even what Trenchcoat jokingly calls a "flower display" in the back seat. Aww, the driver is so screwed. It now occurs to the Driver to ask why Trenchcoat didn't just ring up the doctor, and Trenchcoat takes this as the cue to get the Driver to stop the car, claiming that the doctor lives just behind some trees. This is a big fat lie. As they pull in, Trenchcoat claims to have something for the driver and snaps a chunky metal bracelet around the driver's wrist! The driver is at first amused, and starts to fob off the unwanted gift, when he spots a big square box on the top of the 'gift' and demands, "What is this?"

Trenchcoat has pulled out a gun, and sneers, "Listen to me, Prescott," to the driver. Prescott demands to know how Trenchcoat knows his name, but Trenchcoat doesn't want to natter for long. He tells him to shut up and to listen carefully, because he doesn't have time to repeat himself. Uh oh.

Trenchcoat 'checks' that Prescott is the man who works at the Hudson Building room 1972 (and what if they had the wrong Prescott, or Prescott had just borrowed the car? They'd feel pretty silly then…) – Trenchcoat then tells Prescott that the key to the 'bracelet' is in the top draw in a cabinet in Prescott's office. Prescott is still struggling to remove his gift, but Trenchcoat tells him not to bother as it's made of solid "hydrochromatised steel" and that nothing will break it under 20,000 degrees of heat! Oh, and the box also contains an explosive charge set to go off soon. Prescott looks impressively pale as Trenchcoat sneers, "Are we in business?" Prescott weakly asks what they want him to do. The stranger tells him it's "simple", that Prescott just needs to take off the bracelet in the room and leave it in the draw where he gets the key. Easy. A frightened Prescott calls him "crazy" but his tormentor seems indifferent, and throws in a "friendly tip" that Prescott shouldn't try throwing the bracelet out the window, as he'll "want to get…further away than that!" he's also got just twenty-one minutes to achieve this before the bomb goes off at 8pm, and the Hudson Building is 30 miles away!

Whether it's a big con or not, Prescott is convinced enough to hit the gas, leaving Trenchcoat standing on the kerb. There are lots of CRASH ZOOMS on the clock as time speeds away – just twenty minutes left! Prescott sweats more as the cops notice his frantic speed and give chase. An Irish-accented cop reports the chase to a disinterested sounding controller. The cop asks for some barriers, too, as the speeding Prescott is "gonna take off!"

Prescott's clock continues to tick away, and he bursts through the police barrier, making his wife's flowers tumble off the back seat onto the floor (rather symbolic, really). Serious chords ramp up the tension as we see the Hudson Building entrance, and the music usually reserved for International Rescue's last ditch effort cuts in.

A shifty looking chap is watching out the window of his apartment, enjoying a cigarette. He sees Prescott arrive at the Hudson Building (this little scene handily gets around having to show us much of Prescott's frantic journey into the building). The man's wife calls out – in the background the awesome 'March of the Oysters' plays on their telly – and she asks him who it is. The man recognises the car as Prescott's. At this point we aren't entirely sure how the man knows the Hudson Building employees by sight. The man tells her who it is, but she can't hear him over the noise of the TV. He comments that it looks like something's up and that Prescott must have his own key as the poor man enters the building. Just then the police turn up, sirens wailing. The man asks his wife, Gladys, what time it is.

Time is very much on Prescott's mind, as he has actually made it there with ten minutes to spare. His timing lead is spoiled by the world's slowest elevator (or lift), slowly descending as he waits, drenched in sweat. It seems he'd be better off climbing the forty-seven flights of stairs! He mutters the obligatory "come on" to hurry the lift along. He looks at the lethal bracelet again. Finally, the elevator hits the ground floor and Prescott enters the last stage of his journey.

Meanwhile, the chap who watched him arrive, (apparently he's called Sam and is the Hudson Building's janitor), is chatting to the cops on a special wall phone while he scratches his stomach. He "figures" they wanted Prescott for "something" and Gladys shouts again to ask what the cops have said.

Prescott ascends all too slowly in the lift, while the cops wait outside, sure that Prescott's car is the one they were chasing. The Irish cop, Flanagan, notes that the lights are on on the 47th floor, presumably the location of Prescott's office. Prescott's frantically rifling through drawers here, time continues to tick away. Rather surprisingly, and very sportingly, the bad guys have actually provided him with a key! He gets hold of it with three minutes to spare and rips off the clunky metal.

The cops are still stuck outside but they hope to learn what Prescott's up to once the janitor, Sam, arrives with the key.

While they wait, Prescott stuffs the bracelet back into the drawer and makes a dash back to the lift. Maybe he should have taken the stairs, as it's not going down any faster than before, and it's already time for the bracelet to explode. With a mighty BOOOOM the whole floor explodes and Prescott's elevator crashes to the bottom floor!

Fire crews zoom out with their sirens blaring as the fire spreads, and Flanagan is talking on the phone to a chap in the police station (actually the police commissioner, Garfield). Garfield demands a full rundown once the situation is under control, as the Hudson Building is apparently "government owned" and they "can't afford slip-ups". The building is already on fire, mind you. Apparently the situation is worsening and the "automatic extinguishers" within the building are not working. I have to wonder if the builders of the Thompson Tower ("City of Fire") might have struck again. Garfield is shocked and asks for more about "the guy who started all this". Flanagan reckons that Prescott was caught in the explosion, and as the fire's spreading and the lift's out of action, they can't get near him or the scene of the explosion. Garfield wishes he knew "what the heck this was all about".

There's a disaster happening, so naturally the next thing we see is Thunderbird Five. Brains is there, fiddling with some buttons while John calls base with news about the Hudson Building. Down on Tracy Island, Jeff asks if there's any more news, and John tells him that newscasts are not hopeful and that the fire crews can't get Prescott out. Alan and Tin-Tin are hanging around, apparently back in near-snuggle mode, watching John's report. John tells them all about Brains' theory about the cause of the explosion, which is that it must have been triggered by an incendiary device to have caused this much fire so quickly. Very suspicious. Brains abruptly shushes John as another news report comes up. The fire has destroyed the top five floors of the building, and the janitor, Sam Saltzman and his wife said they were watching TV when Prescott arrived. Police Commissioner Garfield (last seen ordering Flanagan around) says they will have "several charges" to make against poor Prescott, although it does rather depend on the hapless schmuck still being alive and if they can even get him out of the flaming lift.

Alan is still up close with a smiling Tin-Tin, where they seem to be poring over a photo album. The reporter signs off by saying there was little hope that the auxiliary fire fighting equipment would do much good, and Jeff reckons that if that's not "a call to action," he doesn't know what is. Well, short of an actual call to action, yes, once again Jeff Tracy invites International Rescue before the authorities realise they need help. He sends Alan to fetch Scott and Virgil and get them down there "right away" – yay!

Jeff then orders Brains to "put Virgil straight" about which Pod to use, and Jeff is keen for them to try out the new fire rescue equipment. He then tells Tin-Tin to monitor all the broadcasts about the Hudson fire and to keep Scott and Virgil informed. Then he gets to say "Thunderbirds are go!" at the top of his voice. He clearly loves doing that.

Thunderbirds One and Two blast off after absolutely no launch sequences, and Jeff and Tin-Tin (she now has a nifty little headset) hear Brains say he's told Virgil which equipment to pick up, and that he advised him to bring extra "Dicetylene".

Probably wishing that they had some Dicetylene too, the fire fighters battle the flames but it seems to be having little effect. Flanagan is watching events unfold and claims he holds out little hope for Prescott, stuck at the bottom of an elevator shaft which is probably flooded even with their efforts at pumping it out. Commissioner Garfield has arrived now and hears that the safety doors have also jammed shut, so they really can't reach Prescott at all.

Help is on the way! Scott chats to Tin-Tin from Thunderbird One – incidentally, a lovely shiny blue dress for Tin-Tin here! – and she tells him that the fire department really can't do much while Prescott is in harm's way, and that they are also sure that the building's Auto Fire Extinguishers were cut off from the water supply, making things much worse. Scott ponders that there's "more to this than meets the eye". Hmmm. Jeff butts in, asking for Scott's ETA – Scott replies he'll arrive in 9.5 minutes. The fire blazes away and Garfield is told that they've radioed Prescott, and also International Rescue is on the radio with Flanagan. Garfield excitedly demands to speak to them.

In Thunderbird Two, Virgil radios base and asks how Scott's doing. Jeff tells him that Scott's "practically there" and is talking to the commissioner now. He is. From One's cockpit, Scott tells Garfield that if the fire crews can keep the flames under control, International Rescue will "undertake" to get the man up from the elevator shaft. Garfield warns him that the fire's spread to the "basement floors" via the lift shaft. Scott learns a little more about the layout and that the safety doors are jammed. Garfield's men are trying to open these doors but Scott advises him to get the men out of there "right away" and that International Rescue will also want part of the area "cleared for landing". Garfield happily agrees – apparently there's a big space at the back of the Hudson Building they can use. Scott thanks him and then wants a guarantee of secrecy during the whole operation. Garfield enthuses, "You got it, buddy!" Thunderbird One lands impressively at the scene and Garfield calls her a "sight for sore eyes".

Back on Tracy Island, the news reporter is waxing poetic about Thunderbird One's arrival as Jeff and Tin-Tin listen in. Jeff is naturally more concerned about the "man at the bottom of the shaft" than about the "eyes and hearts of the people of Spoke City". To be fair, it seems impossible that Prescott could survive being beneath such a vicious blaze.

However, he is immediately shown to be alive and more or less well, battered and waist deep in frothy water, surrounded by big bits of twisted metal at the base of the elevator cage. Outside, the fire fighting continues. Garfield has gone from being International Rescue's biggest fan to the more typical 'grumpy person in authority' as he waits for International Rescue to leap into action. It's been a whole thirty minutes since they arrived. They really haven't been sitting around, though. Scott is next to the lift shaft, talking to Jeff on what could pass as a 1980s cell phone. He's also forgotten to put on his asbestos suit, as he tells Jeff that the Dicetylene Cage has been fixed up. Jeff wishes them luck and Scott sends Virgil and Alan (who sensibly are in their fire suits) down into the elevator shaft. Alan immediately notes that the heat is increasing, so Virgil sets the Dicetylene sprinklers going. Alan is chuffed by how effective the "stuff" is, but Virgil is concerned that the tank they have might be too small. They keep descending. Scott checks on Virgil's progress and his brother reiterates his concerns about the supply lasting, but they're almost there.

Prescott has no idea what they're up to so he gets worried when a loud thud sounds above him. Virgil radios him to ask what state the elevator is in. Prescott reckons the cage is more or less intact, so Virgil operates their cage's grabs to pull Prescott's more battered elevator cage out. Virgil then tells Scott he thinks they've got him and that they're coming back. As the cage shakes, Prescott exclaims "what goes on?" while Alan and Virgil watch in dismay as the supply of Dicetylene abruptly dries up. So, presumably Prescott now burns to death? Alan nervously asks Virgil if they'll make it, and Virgil growls, "We're just got to!" They continue to rise and Scott waits anxiously. Then it's all over very quickly. Scott greets a stunned Prescott with "You're gonna be all right now" as the lift cage emerges with the poor guy now safe and sound.

It seems to be the morning after the fire, and after a quick shot of the scorched tarmac and a rather watery Hudson Building, Garfield discusses Prescott's bizarre story with Flanagan. Garfield is sceptical and baffled by why a man like Prescott would go out on his wedding anniversary and commit "enough offences to give him twenty years inside". Flanagan agrees that Prescott had a spotless record before that night, and Garfield decides that he believes Prescott's story. After all, the fire had destroyed files on many of the "most vicious gangs operating today" including the sinister-sounding "Erdman Gang". Oh, and there was the small matter of the 'Automatic Fire Extinguishers' being put out of action. Garfield muses, "It adds up, you know". I'd like to point out that Scott only really needed the second clue to figure out that much.

Another cop enters with Prescott's bracelet retrieved from whatever was left of his office. Garfield exclaims, "That's it!" and immediately sends for the FBI, determined to get to the bottom of this "even if it means employing a little deception". He looks triumphantly to the camera.

This "deception" is rather detrimental to International Rescue's reputation (not to mention what it's doing to poor Prescott's marriage). In the Spoke City Tribune, the headline screams that Prescott perished in the blaze and that the "Mystery Explosion Remains Unsolved". The date on the paper also appears to read December 24, 2067, although it's very hard to tell without Hi-Def! (There is also a glorified calendar calling itself an "Auto Date Fixer" on the wall in the office, which reads July 13, 2005 – it just says 05 as the year, but they surely don't mean 1905! – so it's anybody's guess what date this is really supposed to be!). Tin-Tin is wearing yesterday's dress, and is rather shocked by the headline of the newspaper. She had thought Alan had saved the man, and Alan protests that they "did, too!" and asks his father why they would publish this. Jeff thinks that the authorities have "some kind of scheme lined up" – and I can't help thinking that telling International Rescue a little about it would help avoid any embarrassing press release snafus. Scott sweetly wishes there was something they could do to help Prescott, as he "was a nice guy". Alan is dying to get involved, but Jeff reckons these things are best left to the FBI and Interpol. He figures that they're trying to draw "whoever's responsible" into trying the same trick again. Given how much International Rescue know here, it seems likely that Prescott blabbed the whole story to Scott once they pulled him out. But that's the end of International Rescue's part in the mystery, for now.

Now we're in London, looking through some trees at Big Ben. In a secret room, two hats are talking. This scene proves that the Anderson team watched far too much Bond while they made this show. Possibly they'd also run out of puppet heads. Either way, this is a very cheap technique as each hat gets its own 'voice'. An upper class British voice offers an American more tea; the American replies "Er, no…" Nonplussed, the Brit assures the American voice that 'Southern' is the best man for the job. The American says he'll need to be "tough" to handle the Erdman Gang. So, this is a meeting investigating the Hudson Building fire. Southern himself arrives and adds his hat to the rack. In pure Bond style, we see his hands are given a pen which is also a radio gadget, and then he's sent off to investigate the Erdman Gang.

More hand acting ensues as an evil Russian voice (oh yes, this is the 60s!) reassures the recipient of another bracelet that the 'Leader' will issue instructions once they reach Kilkenny Castle in Scotland.

The castle is definitely haunted. The camera pans past sinister portraits and flickering candles, and a creaky door as well. I think the Anderson crew had been going to too many Hammer Horror/James Bond double bills at this point. We see three men sitting around a wooden table, playing cards. Two of them are definitely no-good crooks, complaining in weasely voices about how cold this "dump" is as they're stuck there awaiting their orders. A man who can only be Agent Southern himself – and shall now often be dubbed Worst Spy Ever – agrees in his poshest voice that they have been there for thirty-six hours without hearing a "peep". There's a nice shot from above their heads as the three men sit under a creepy castle chandelier. The 'Leader' picks that moment to speak on the radio.

The two weasely-crooks, resting on a pair of bagpipes, listen intently as the Leader outlines his twisted plan's final details. Like Trenchcoat, he will also only "go through it once". He tells them they will leave the castle at 0900 hours – which Southern repeats to his secret pen radio. The Leader orders them to drive to the Nuclear Plutonium Store which is marked on their route maps, and explains that it contains all the isotopes for all of Britain's nuclear power stations. As he describes what will happen, the footage of it appears in fuzzy-round-the-edges vision. The Leader explains that each gate is guarded by a dangerous robot, and it's pointed out that there aren't any people at this facility. Southern's pen is framed in front of the shot as he listens. We learn that the alarm systems have already been rendered ineffective so all they have to do is zap the robot guards with a neutraliser and get into the building through the steel doors. The Leader warns that they must be in the main storeroom with the plutonium vault by 0930. Then they will set the fuses and drive south to rendezvous with his helijet. The crooks are gleeful "that's when we get paid" and the Leader confirms that this will happen, if they are successful.

Southern muses that they're "going to meet you at last" and the Leader repeats, only if "it has all gone well will you have earned that honour". As Southern repeats the information, presumably for the benefit of the pen radio, the dark haired crook, Dempsey, snaps at him to quit asking questions and "playing around with that pen!" Southern snaps back, covering his actions by saying how important it is to get the timing right. The Leader says that Southern is right – and he called the 'secret agent' Southern by that name. Worst. Spy. Ever. The Leader then gleefully tells them that three hours after they set the fuses, the nuclear storage bunker will explode – and in the special future-vision, we do see it EXPLODE very convincingly.

There's a lovely switch here as the flames of the facility merge into the fire in front of the three men. Southern is still curious about the fuses and wants to know where they are and what time they must be set for. The Russian Leader cackles that he was "waiting for one of you to ask me that" and the other two look rather annoyed. The Leader tells them that the fuses are set "at this moment" and they are locked onto their wrists! The crooks are appalled but the Leader says it's a "precautionary measure". The key that will unlock the bracelets is apparently also the key for the vault mechanism. Which makes me wonder – if this evil gang has so much great access already, why the hell do they need these chumps to go in there under duress and do the work for them later on? Especially if they actually honour their agreement? Then again, this was the 1960s. I'll just have to let it go.

Southern has another question – where is the key kept? Apparently it's in the box near the vault door, and the Leader signs off with the cheerful reminder that if they fail they will "all be blown to kingdom come". The guy knows how to motivate. Southern tells a grumpy Dempsey to come on, "it's time" and Dempsey grumbles, "don't rush me". The other guy, Kenyon, is quite impressed by the "smart" idea of attaching the bomb to their wrists. Southern agrees and then urges them to "get moving!"

Now, at the nuclear storage facility, the three men pull up outside as planned in a red convertible with white stripes. As the robot guard patrols inside the first gate, Dempsey announces that they're "bang on schedule" and tells Southern to "fix that robot". They zap it and it clangs to the ground. The "dangerous" robots here look like Brains' robot, Braman's bigger, meaner brothers (see "Sun Probe"), and they're about as useful, and three times as slow. The crooks and Southern then blast open the gates and the evil plan continues to run like clockwork. As the second gate opens they zap the next "dangerous" robot with ease and there's just one more door after that, then they're at the plutonium vault. Southern take a while to get the second-to-last (slightly more "dangerous") one, but down it goes. At 0920 they enter the vault area and Dempsey is dying to get the fuse off his wrist. Kenyon hustles for Southern to "make with the ray" but Southern worries that he can't see the final robot. Kenyon is clearly more concerned about the explosives on his wrist than a ponderously slow mechanical threat, and snaps "who cares?" as the crooks urge Southern to get hold of the key, starting to freak out that if the charges blow too soon they'll be "dead men".

Southern obliges, blasting the lock, but once he has the key he pulls a gun on the crooks and orders them to stay where they are, announcing a "change of plan". The other two look shocked and tell him to "quit clowning" and to "unlock these bracelets" and at this, Southern goes a bit evil. He wants them to do something for him, first. As they freak more about the shrinking time he snaps "shut up and listen" and orders them to go and meet the leader, then to bring him back to him. Do your own dirty work, you lazy agent! Dempsey snarls, "I didn't like you from the start" which is fair enough. Southern channels Roger Moore rather than Sean Connery, and he seems more like 'The Saint' than James Bond, which Roger Moore was playing at around this time on the TV. Southern does a supercilious sneer that the "first rule of security (is) don't trust anyone". He should listen to himself more, as the fourth robot has finally woken up and is lumbering its way towards his back.

Southern remains oblivious as the two crooks play for time, asking why Southern is ruining a good thing. He sneers, "You wouldn't understand even if I told you," and at that point the robot starts trying to hug him to death. His gun clatters to the ground and he sounds like the robot's grip is extremely painful. Maybe this one finally looked up the word "dangerous!" Kenyon tells Dempsey to get the key and chortles that "things worked out for us after all!" Dempsey removes his bracelet and tosses Kenyon the key. They also take off Southern's bracelet, just in case perhaps, and then place the charges "as arranged". Kenyon gloats to the Worlds Worst Agent that the place will "go up" in three hours, "and so will you!"

Dempsey is paranoid that Southern could have a partner who could rescue him, but Kenyon's already got a plan – that they'll jam all the electronic doors so that no one can reach the WWA in time! With their plan all set and the clock ticking, they rush off and leave Southern stuck in the robot's embrace, with the evil looking bracelets stacked up next to the plutonium vault. Southern swears that they "won't get away with this!" but Kenyon sneers, "No one can stop us, least of all you!" And the screen fades to black.

Next, we're still at the nuclear bunker as the crooks shoot up the controls. Southern, with his 'real' hands, struggles to retrieve the radio pen from inside his jacket. He calls HQ using his codename of 'Agent Tiger Four' which just convinces me that they're letting him do this because he's some government minister's son who's always wanted to play at being a 'secret agent'. A rather irritable 'Two-One' answers, saying grumpily that the channel is only to be used for emergencies (and again, I have visions of Southern being unable to leave his gadgets alone and harassing his poor boss). Southern retorts that this is an emergency and explains that basically the mission has been screwed up and that fuses are set and the nuclear store will explode at "1230 hours". Two-One says that they'll go up and release him, but Southern protests that there's "no time" as the doors are jammed. He urges them to evacuate the area – presumably the nearest thousand miles or so. Two-One exclaims that they have "less than three hours" but Southern says "listen to one" (a line I always found funny) and he says that if the fuses go off it'll "cause the biggest explosion the world has ever seen." They must try to evacuate. For some reason Two-One still wants to try and save him, but Southern is adamant that they do not come after him.

The crooks have only just left the building and are finishing off their sabotage of all the doors. Next for them is a "long, fast drive" to get their payment from "The Leader", and evacuation from a nasty nuclear accident is a helpful plus.

Twenty-One tells Southern that someone at HQ has come up with a plan that might save him, even though Southern protests that no one could possibly reach him in time. Um, except perhaps International Rescue! Southern immediately wonders if International Rescue will also stop the rendezvous with the Leader. The Two-One is less sure they'll do that as "they're strictly a rescue organisation, not a police force," but Southern reckons it's "worth a try".

Thunderbird Five picks up Two-One's call. Southern's boss announces himself as "Sir William Frazer of the British Secret Service" – does no one bother with a secret identity anymore? He also tells John he's called, "Code name Two-One". Oh for crying out loud….

John tells 'Two-One' to go ahead, and clearly didn't expect to hear that a British agent is "sitting on top of a nuclear explosion that'll destroy half of England" (well, most of Scotland anyway). John's response is an understandable "Wowee, that's serious!"

Alan, Tin-Tin and Gordon are out fishing on a boat near tropical Tracy Island. The trio are so chilled out that Tin-Tin has donned a turtle-neck sweater and parka jacket while she fishes in the clear blue water. Gordon muses that there's "nothing like fishing to relax the mind" and Alan teases him, saying, "Or the body, if you're any example!" Maybe he's sore that Gordon's there as chaperone? Just then, Tin-Tin gets "a bite!" and Gordon advises her to "play it for a while" and to "give it more line". There's no more time, though, as Jeff radios urgently for them to return. Alan goes to start the engines, and Gordon advises her to bring in the catch. She's trying, but she "thinks it's a big one this time".

Her suggestive words are echoed by Jeff a second or two later. Brains is there and recommends that Scott and Virgil get going as they have just two and a half hours left. Virgil sounds a little awed by the extreme emergency, "Boy, are we gonna be tight on time!" Which prompts a clipped, "Yeah, let's go!" response from Scott. Virgil's still thoughtful, musing that he'll take Pod 5 with the laser-cutting equipment. Good call. As the brothers dash to their machines, Brains asks Jeff what they should do about the rendezvous. Jeff acts all above-board, reminding the scientist that it really isn't their job to catch crooks, "no matter how dangerous they are". Brains is aware of a loophole, however, pointing out that their "agent in Britain" could help. Who could that possibly be? And why does it suddenly feel like they've only just met her? Jeff agrees that this mission "should be right up her street", (or estate, perhaps?) I hope Jeff realises that he's about to sign the crooks' death warrants, as moral ambiguity is not Lady P's strong point.

The Lady herself is taking tea in the drawing room, in a scene that looks redubbed from Trapped in the Sky. Jeff contacts her via her wacky teapot-radio (it was the 60s!) and tells her "This is a hot one!" He asks if she's free to stop "enemy agents" fleeing the country, and gives her a reference point, adding that she'll need to hurry. She calls for Parker, and tells him to get the Rolls-Royce as they will be "heading North", and to "hurry".

Scott's hurrying so much there's no launch sequence yet again. Thunderbird One blasts off, immediately followed by Two. Action stations, guys, and time is short.

FAB1 zooms along the motorway. Parkers asks her Ladyship if she thinks they'll make it, and she replies that it will be "touch and go" and that they can't afford any hold-ups – thereby ensuring they will have several later on, to ramp up the tension. I think she must have paid off all the British transport police cops to get away with that speed.

In TB1, Scott calls Virgil asking for an ETA. Virgil reckons he'll be there by 1210, which Scott figures gives them barely twenty minutes to get into the plutonium store and finish the rescue!

FAB1 is now trapped behind a big, slow lorry loaded with nitrogen. Concerned by the shrinking time, Penelope urges Parker to "give him a toot," and they finally zip past it in a garish pink blur.

Scott has now arrived and brings One down to land. He sharply tells Virgil to "hurry it along" and says he'll take a look around and try to contact Southern. After he's finished landing, he gets though to the trapped agent and tells him to "sit tight," as Thunderbird Two will be there in five minutes and that they'll "soon" have him out. Southern repeats his martyr act, begging Scott to get himself to safety, but Scott replies with a confident drawl of, "…We've come a long way to get you out and that's exactly what we're gonna do." When Southern repeats his 'get out of here' plea, Scott tells him, "International Rescue doesn't give up that easy". Awesome.

Right then, Virgil calls – he's coming in to land at last. The Pod lifts up and excited music plays over the reveal of this episode's very teeny pod vehicle. It's a little tank like the one International Rescue used to get the jet packs up to the men in Edge of Impact. Virgil trundles it over to the nuclear storage building. Scott is leaning against the nearby wall and tells Virgil they will have to "work fast" as "those doors are jammed tight!" and Virgil wonders about blasting in instead. Scott dismisses the idea as too dangerous, given the bracelet fuses and all the nuclear material within. He makes a good point. Looks like they'll be laser-cutting their way in as planned. Virgil tells him to stand back, and off they go. Scott warns Virgil that there's just fourteen minutes left, and two more doors to go after this one! Virgil sets the huge 'auto-timer' (think glorified stopwatch) for the countdown. There's another nifty camera angle as Scott watches the laser nozzle go into action whilst standing some distance behind it.

While the Tracys work, FAB1 busts through a diversion sign somewhere in the (very scared) British countryside. The Angel of Death is getting closer!

The first door is nearly fully lasered open. Virg says "OK" and blasts at it with some kind of force wave. The door blasts apart and the way is clear. There's a close-up on the lethal countdown, and Scott rides on the side of the cabin as the laser cannon trundles on and they start on the next door. Virgil even gets to have his, "Come on, baby," moment as the laser does its work. We see Southern is still struggling against the robot's immovable metal arms. Also, the fuses wait ominously in their little stack of doom. Scott is anxiously guiding the laser nozzle with his hand as Virgil finishes, and comments, "That's better, stand by for jet blast!" before he blows the next set of doors apart.

FAB1 is still moving at speed, taking an unorthodox 'shortcut' by smashing through a gate into a field, and making a joke of a sign politely requesting users to keep it shut. We can add property damage and livestock endangerment to Lady P's list of misdemeanours so far, and all because Agent Southern's spacial awareness isn't up to scratch.

Southern is still struggling with the robot, and he moans that he still can't get free. I'm not sure what he'd be able to do by now even if he could, apart from throw himself on top of the charges – and that's no use unless he's made of Adamantium or something. The fuses begin to smoke, and the Tracys are at the last door with seven minutes to go. As the laser crawls halfway around the barrier, Scott urges Virgil to "try the jet now" as "time's running out!" So Virgil obliges.

The jet blast throws open the last doors. By some miracle they don't also flatten Southern and the robot into pizza topping. Scott exclaims "I gotta get those fuses," and orders Virgil to take care of the robot. Scott rather gingerly gathers up the three lethal bracelets and then exits at top speed. Virgil gets to work helping Southern, assuring him, "We'll soon have you free" and I imagine he's trying hard not to imagine his brother getting blown to pieces outside.

Scott dives into One's cockpit and takes off. Better hurry, Scott. He's put the bracelets on TB1's hatch door and they're smoking away worryingly. Scott, sweating at the tension, flies low over the sea and releases them with seconds to spare! By another miracle they somehow don't slide off the hatch and back into the cockpit. The fuses hit the water and moments afterwards the sea erupts with explosions.

Scott reports to Jeff that he's succeeded, and that this is probably the last time the Erdman Gang can "try the bracelet trick on anybody," although I honestly don't see why, as it seems to have worked pretty well so far. Jeff agrees that poor Prescott is now "fully vindicated," and Scott adds that all remains is for Penelope to "tidy up the details". Yes, Scott, it's the Angel of Death's time to shine.

Penelope tells Parker that the rendezvous is in the "next field" and that she can hear their helijet. I'm still impressed that the characters are finally calling them helijets, rather than 'copters as they've been doing all through the episodes before this. Dempsey and Kenyon have made it into the Leader's helijet, unaware of Southern's last minute rescue. Kenyon gloats that he's "glad" things turned out the way they did, as now he and Dempsey get "a bigger share of the loot". Dempsey has just realised this too. The Leader is gleeful, and "all" they have to do now is "escape into safety, and that should be quite a simple matter" – although isn't this rendezvous happening after the great big explosion that was meant to kill everyone? The Leader also hasn't spotted the shocking pink Rolls-Royce of Death approaching across the field. As he lifts off, the cannon emerges from FAB1's grill, and opens fire. The helijet goes BOOM and collapses. No one's walking away from that one – but to be fair, they were trying to blow up the UK, for money.

There's very sad music playing over the next scene, as Virgil and Scott take care of the Worst Agent Ever. Southern is lying unconscious between them on the floor, but Virgil has made him up a little folded blanket headrest and is patting the guy's head as he half-kneels beside him. Awww. Virgil sadly tells Scott that Southern is "in a bad way" and wishes he'd been able to "release him quicker". Scott consoles him, saying "you did your best" and noting that, "those robots aren't the easiest guys to handle". Scott adds that he'll call for an ambulance (not just nip over there in TB1?) but just then FAB1 pulls up. Apparently Penny can cover the distance of a three hour rendezvous in about two minutes.

Virgil wonders how she "got on" and Scott asks her, "Success?" and she replies, "Success," which is all rather formal and succinct. They either know each other well at this point, or they're maintaining a professional distance. Scott then introduces Penny to the unconscious Southern, and tells her that the agent needs "hospital attention". She tells Scott to "get him in the car" (with his internal injuries? I hope they have a stretcher) and that she will take Southern to hospital herself.

Much later, it's night time at Creighton Ward Mansion. Penelope is dining with Southern in front of another roaring fireplace (excellent use of puppet perspective and scale in these shots). I always assumed that she was keeping him around for interrogation purposes after his recovery. He tells her she's been "very kind," and she sweetly asks if he's "fully recovered" now. He assures her he's "as fit as ever" while he chomps on a big cigar. He laments the end of his career as a secret agent. Penelope plays girlishly innocent, enquiring why that is. He patiently – and rather indulgently – explains that his cover is now blown (Ahem. What cover was this?) and gruffly tells her that secret agents can't operate unless they're incognito. Then he patronises her further by saying, "a person in your position wouldn't know that".

Penelope momentarily forgets that her secret identity is very much intact (who knows how) and agrees, "Oh, no…of course not". She butters Southern up more by adding, "It does sound fascinating, do tell me all about it". I wonder if Southern checked his meal for truth drugs? The ex-agent acts slightly bashful, but she continues to charm him, saying that she'd always have liked to "do something exciting" like secret-agenting. Southern rather archly tells her that "it's not all romance," and that in reality "it's a tough existence," as you're "never being yourself". He stirs in some more patronising comments, commenting that someone like her, "so sheltered and gentle," just isn't "the type". Wow, she's really been playing him here. He tells her pompously that, "We walk with danger as a shadow. Death is a constant companion." (I think he's practising for his book deal here.) And he instructs Lady Penelope, Angel of Death, to just be what she is, "A very beautiful lady".

Penelope takes this back-handed compliment rather impassively, and as the camera pulls back from her face I like to imagine that Parker is sneaking up behind Southern with a dart gun, ready to drag him off for some healthy interrogation.

Despite the dodgy secret agent, this is a thrilling, well-paced episode that brings together a very sadistic bad guy scheme and some innocent, and some not-so innocent victims in peril, all providing plenty of action for International Rescue. This is certainly one of the more ambitious stories with big scenery changes and an impressively large cast of characters. The pacing is especially good, and the lack of padding is clear as there's barely any time for the Thunderbirds to launch. The bracelets are also a great, creepy idea - it's a little like a kid's version of a Saw movie, in places. Or not. There's also some very inventive camera work, and I don't think I've seen more use of 'real hand acting' in any other episode.