I always feel that this episode demonstrates the show’s purest intentions. It seems to take forever for the Thunderbird machines to show up, but there’s a lot of care taken with the setup.

We open on a long series of stock footage showing live-action animals and jungle scenery. Cute safari music plays over the top. It changes abruptly as a metal claw swings into view and rips a tree out of its way. The cute – and not so cute – beasts scatter as something enormous muscles its way through their dense rain forest. A wobbly-looking metal leg thumps the ground as it moves. Here the music makes me think of a rather grumpy elephant.

When the metal monster is revealed, it resembles a cross between an AT-AT from Star Wars and an elephant from a Salvador Dali picture (albeit a stumpier version). It belongs to the World Army, and a helicopter has been following it. Inside the ‘copter, a man named General Peters chats to his colleague, Ralph. We learn that the weird machine is named the Sidewinder, and will be useful for calming the bush wars in this part of the world which otherwise they couldn’t reach. I hope he realises he’ll be stalked by angry environmentalists, too… the thing could clear a whole rainforest given half a chance.

The General gets in touch with Sidewinder’s crew; a man named Colonel Sweeney plus two other men. They’ve been testing the big tin can in the jungle for three weeks, and they’re understandably keen to get back to civilisation. They’re told to head for the next rendezvous position, where they can leave the Sidewinder to the mechanics. The helicopter – tagged ‘Copter Watchdog,’ flies away.

Of course, no experimental craft ever lasts long in the Gerry Anderson universe, and the Sidewinder is no exception. As it begins to stomp, the ground underneath it cracks and crumbles violently. Lots of dirt flies up in the air, the jungle explodes once more, and then the earth swallows the Sidewinder whole!

No, International Rescue still aren’t in it yet. Be patient…

General Peters catches on that the Sidewinder’s not responding, and heads back to take a look. All that’s left is dirt and miles of smoke coming up from a crater. The General frantically tries to call his crew and they very slowly come round. At this point I realise that the crew member named Johnny is voiced by Shane Rimmer. Which pleases me even as it confuses!

The crew report that they are about 300 feet beneath the surface. Worse still, they’re upside-down, which means they’re completely stuck. It’ll take heavy lifting to raise the 500-plus ton machine and the General grimly realises they’re so far out in the wilderness that no one can reach them anytime soon.

It’s reaching 220F outside the Sidewinder’s hull and Sweeney has even more bad news. The atomic reactor requires refuelling. When it runs out, the cooling system will stop working. They’ll be fried. No one learned from Fireflash, then! Maybe International Rescue need to publish some sort of advisory booklet on maintaining nuclear reactors, so that they’ll last the extra ten minutes before help arrives!

So, desperate measures are called for. Yet it’s not so desperate that they call International Rescue yet. We’re still at the point in the series before they’re instantly called up, or have to make their own emergencies to shoehorn in Lady P. But more of that in later episode commentaries.

For now, the World Army have to make do with their own resources, and this involves sending down two volunteers to examine the Sidewinder’s position. Bear in mind that the pit it’s in is ON FIRE and all these guys have to protect themselves is a breathing mask and some wet cloth. I know they can’t get hold of heavy lifting gear in time, but you’d think they’d have taken thirty minutes to source a couple of fire suits and a pair of gloves!

Anyway, the first guy, Lieutenant Mead, is winched into the pit to check out the Sidewinder and only gets a little glimpse before he’s screaming in pain. Highly disturbing. Mead is hastily yanked out, covering his scorched face with his hands (again, highly disturbing). The ‘we’re so screwed’ music plays.

While this attempt is going on, we’re fifteen minutes in and guess who’s listening in from Earth’s orbit? Radio monitor, John Tracy, of course, in fabulous Thunderbird Five. John picks up that things are pretty desperate, and contacts base. Jeff Tracy is chatting to Scott and Virgil when the call comes through and the three of them listen to Mead’s doomed effort.

Scott’s naturally eager to blast off and help the guys in trouble, but Jeff vetoes the idea, as they “can’t go uninvited”. (Which namechecks an upcoming episode, a little. Sort of. ) Anyway, Scott’s enthusiasm lands him on ‘standby’ duty, where he gets to sit in Thunderbird One waiting for the go signal. I’d like to point out that Virgil continues to lounge around in the Tracy house ‘til he’s actually needed, but I’ve gotta give Scotty full points for enthusiasm!

Whilst Scott twiddles his thumbs, the army guys argue over who ought to go into the pit of certain peril next. The General’s buddy, Ralph, volunteers, but Sergeant Reynolds reasons that he’s the better choice. It seems that their next plan is to hook a loop of metal wire around one of the Sidewinder’s legs and hoik it out that way. So the Sergeant is lowered down – what, still no gloves? Just call International Rescue, you morons!?

Amazingly, Reynolds actually succeeds in hooking the loop over the Sidewinder’s leg before he, too, starts screaming in pain. They pull him out and send the secondary helijet to take him to hospital. Then they try to lift, or at least turn over the Sidewinder using the army helicopter. Which is a bit like Nicole Richie trying to land a blue whale. It’s just not physically possible.

Even more amazingly, though, this almost succeeds in at least tipping the Sidewinder upright, which allows for some lovely smoke effects against the wonderful, grungy model work. Despite their efforts, however, the Sidewinder slides inexorably over onto its back again. Ralph wants to give it yet another try, but the General is getting increasingly frustrated, and wishes they were closer to civilisation (although I’m sure there’s probably a Starbucks lurking a few feet away). Then they could get some decent equipment in for a proper RESCUE.

That word finally reminds Ralph of this little organisation he’s heard of…

The official call goes out, and finally, Scott can blast off! Happy, ‘they’re on their way’ music plays.

Scott has snapped into full rescue mode and rapidly assesses the situation. Going from John’s info, he calls for Thunderbird Two to be loaded with Pod Five, and for Brains to come along to help work on the crater. Virgil hops off the couch and springs into action, with a very stately launch sequence for Thunderbird Two… I can only imagine how fast it’d all load these days, but nobody rushes the big green machine. No siree.

Then it’s Whirrr-click-BOOM and Virgil’s away, too.

The guys in Sidewinder are worried about the aircon, whilst the General grumbles that IR are taking their time. Which is, of course, when Scott shows up and lands. Scott learns that the radio’s failed in Sidewinder, but we know that the air purifier is on its last legs and the heat is increasing. The General reckons there are two hours left. Scott reassures him, and sends in a little camera device to check out the Sidewinder.

According to Scott, this floating milk bottle is “specially constructed to withstand extreme heat”, but he still sounds kind of relieved when the thing actually works! At this point, Virgil lands and Scott goes over to TB2 to watch the camera’s footage. The General continues to rant that IR aren’t working fast enough.

The apparent inaction is due to Brains and a serious-looking Scott and Virgil analysing the camera’s results. They really are at their frowniest here. Brains figures that Sidewinder, ironically, fell into an old military equipment dump which had been slowly smouldering beneath loose dirt for years. They’ll need to remove the crust before they can pull Sidewinder clear.

So, this time it’s the fearless Virgil who’s being lowered into the pit. Fortunately, he came fully equipped with a protective suit. (The wuss!) When he reaches the bottom, I love the way he says “the smoke is too dense” as though he’s kind of peering through it, whilst his voice is still at its calmest compared to Scott’s. Virgil begins to lay explosive charges. Scott directs him and the army and then heads over to IR’s drilling machine, intending to get Virgil out before detonation! Come to think of it, wouldn’t it have been easier to use the Mole to get Virgil into the pit in the first place?

Well, I guess that’s why they’re IR and I’m just the reviewer…

While this is going on, the guys in Sidewinder aren’t doing so well. There’s just eight minutes of coolant and purified air left! But Virgil’s almost finished, and up on the surface, Scott brings out the superbly designed Mole – the iconic big drill on wheels. At one point, the Mole hits some tough rock and Brains has to redirect him. For some reason, I find the moment where Scott says “Turn me” here rather funny.

This is a great team effort, as Brains waits for the Tracys to get clear, so that he can detonate the explosives. Everyone strenuously explains exactly what they’re doing as the Mole withdraws and Scott sweats in his close-up. The Mole pops up out of the ground – on some reversed film footage. Now they’re clear, Brains gets to blow it all up!

So, we get our explosives fix – and the International Rescue Team are on the last part of their rescue. This is just as well, as Sidewinder’s cooling unit is about ready to give up, and the General’s climbing the walls.

Brains reassures the General as Virgil brings out the next bit of Awesome International Rescue Equipment™. The Recovery Vehicles are like the Elevator Cars, only they have magnetic plungers attached instead of those springy platforms. Virgil controls all three again, seated in one whilst using remote radio for the other two. I just hope that the Recovery Vehicles are a tad more reliable.

In the control car, Virgil looks appropriately grubby after his walk in the crater’s inferno. He’s only taken off his helmet and he’s looking good in the white fire suit. Now it’s all up to him again. He fires the plungers and they connect to the Sidewinder with some satisfying THUNKS.

Lots of skidding and grinding follows as Sidewinder is pulled inch by very painful inch up the side of the pit. Of course, one line fails for a heartstopping moment. “Let’s hope it’s not damaged,” Virgil mutters as he reels it in to try again.

There’s a terrific score playing over this, emphasising Virgil’s tough battle to haul the Sidewinder’s immense weight up the jagged, crumbling slopes. The tension increases when the Sidewinder slips, but Virgil keeps going and then – then – there! They did it!

Sweeney just has time to register that they’re out and to marvel, “It’s a miracle!” before he collapses. Dream music and a swirly screen lead us to his recovery in a medical tent. Scott is there, watching over him and the other two men. Scott obviously wants to make sure they’re okay, and stays long enough for Sweeney to thank him, and IR, on behalf of his crew. Awww.

Virgil takes off in TB2, whilst Scott chats to the General outside. I like to think that this is because Scott’s the military guy, no question. The General’s snarky attitude has completely changed; he’s very happy now about International Rescue’s success. Scott accepts his thanks and requests the General’s secrecy. Then he takes off, and the General wishes he had guys like that in his army. Well, he probably would, if he could be bothered to get heat-proof suits…

So, overall, this is a PURE International Rescue adventure. Can I point out that all this happened without the need to find a reason for Lady Penelope to show up? Or even the Hood plotting a disaster (although conspiracy nuts, please, go nuts). What we had here was a desperate situation, good people in peril, and IR only getting there at the very last minute to succeed within a whisker of failure. I particularly liked the character of the General, whose understandable impatience flips around the minute they pull it off.

This is a solid episode that can at times seem a little dry, but definitely demonstrates International Rescue working at their best and smartest.