It's one of the most dangerous stunts performed in a car and almost certainly the most dangerous stunt performed indoors, so don't try it at home. Even the smallest miscalculation could spell disaster for the Stig as he attempts the loop of death - a 360-degree vertical loop during which Top Gear's resident racing driver pilots a dune buggy upside down.
Some readers will be familiar with the children's toy Hot Wheels - miniature cars that drive upside down round a loop of plastic track. This, for the first time in an indoor arena, is the real-life version.
The trick has taken two months of rehearsals to perfect, and longer still in the planning stage, says Rowland French, the (relieved-sounding) producer of Top Gear Live. "About three months ago the loop was completed and for the first time we knew it was going to be possible," he says.
The Top Gear Live team recruited some of the best minds from structural engineering, together with world rally championship mechanics and experienced stunt teams. "It has been more like building a bridge than doing a stunt. I don't want to give too much away but it was a massive project with every part of the stunt having to be worked out to the nth degree. If anything wasn't right - from the speed of the car to the length of the loop - it would all end in disaster. It was as much to do with maths as anything else," French claims.
Has the Stig been practising hard? Not according to the other drivers in the show, who participate in the choreographed chase sequence leading up to the loop of death. "He seems to know the sequences without having to do rehearsals," says Paul Swift, one of the stunt drivers. "He just turns up five minutes before the show and away he goes. We are all completely in awe of him; I don't know how he does it and then goes to sleep in a shed. You'd think he would need a good night's sleep before something like that."
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Swift - who some people have mischievously suggested is in fact the man beneath the famous white helmet, a claim he vigorously denies - says there is no other driver in the world who could perform the stunt. "It's a good job we've got the Stig. Any lesser driver would end up upside down on fire.
But he is very rude; he doesn't speak to any of the other drivers. We've tried having conversations with him but obviously he is quite arrogant."
People attending the Top Gear Live event - which forms part of the MPH show that kicked off last week in London and moves to Birmingham this week - will see for themselves whether the arrogance is justifiable.
Amid the mayhem orchestrated by the Top Gear presenters, Jeremy Clarkson, Richard Hammond and James May, it is the Stig who rounds off the performance with the stunt that the production team claims is the most ambitious of its kind to be attempted.
The loop is as high as a three-storey building and has had to be made tough enough to complete countless stage performances as the Top Gear Live show travels the world, from the UK to as far afield as Australia.
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Looping the loop has its origins in the 19th century. During the 1850s a centrifuge railway was built in France that allowed paying riders to take their chances at performing loops in a one-man carriage with nothing other than its momentum keeping it on the track - just as the Stig is experiencing.
A buggy from the British manufacturer Rage Motorsport has been adapted with a revised 50-50 front-rear weight distribution, a strengthened suspension and new gearing for the transmission.
It carries the fearless driver in white through the loop. "We have to be aware of where the weight is, where its centre of gravity is, how quick it is over a certain distance," says French, adding that, much like a theme-park ride, the steel loop and buggy are checked and rechecked every day. "There's a whole load of facts and figures that we have had to plug in, so we have built the car from the chassis up."
To limit the room for driver error, the Stig is getting a little help with the stunt from an electronic software package programmed with the critical entry speed for the loop. Too fast and the Stig could black out from excessive g-force; too slow and the buggy will tumble to the ground, giving audiences more than they bargained for.
If you leave the Top Gear Live arena feeling inspired, remember that this stunt has been created by professional people in a closed environment. So, once again, don't try it at home. Not even if you're wearing a white suit and helmet.