How Surtees became champion

If you were writing a treatment for a Grand Prix movie aimed at a domestic audience, it might go something like this: two British World Champions in their blue-blooded British cars battle it out from race to race throughout the season, heading for a title decider in the final race, which is what duly happens.

Except – and here’s the twist – out of nowhere comes a third, an upstart from another team who before this season has won just one race at the top level of the sport. He’s British too, but his car is not: it is Italian. Which makes him the enemy. As the showdown begins, 7500ft up in the thin and dirty air of Mexico City’s eastern suburbs, all know that in two hours’ time one of them will be World Champion.

What none of them yet knows is that the destination of the title will not be decided by any of them, but a fourth driver whose part in proceedings is as unexpected as it is extraordinary. And it will all go down to the final lap.