Clark, a reserved Scot, was among the most versatile and naturally talented drivers of any generation. It was not in his nature to seek praise, and certainly not to display anything more extravagant than a self-conscious wave as he slowed down after victory. But somehow in the summer of 1967 at Silverstone he was persuaded to ride on a trailer behind a tractor and take one more encore from the crowd after a triumphant British Grand Prix win, his fifth, at an average speed of 117.64mph. It was to be his last appearance in his favourite race and the jubilant, appreciative reaction of the crowd was like a strange, collective premonition.
At the start of that season it was obvious that the Lotus cars Clark and Graham Hill were to drive needed more powerful engines. By the time new power units arrived it was too late to give Clark any real chance of winning his third world championship, but when the Lotus 49s were equipped with the new V8 Cosworth Ford motors they were immediately successful. Clark won at Zandvoort with a car that had more or less come straight out of a packing case.
He and Hill were quickest in practice at Silverstone and though in the race Denis Hulme, in a Brabham-Repco, recorded the fastest lap at 121.12mph and went on to become world champion, Clark kept ahead of him to win. He was at the height of his ability and, as a result, in enormous demand. He was not only driving in Formula One and Two but had become a star of saloon car racing in the sleek Lotus-Cortina and even found time for some rallying.
Towards the end of the 1967 season the Lotus 49s were so fast that he and Hill tossed to see who should win at Watkins Glen. The idea was that there was no point in endangering each other's chances. Hill won the toss but in the early stages of the race his car had clutch trouble and Clark won despite a collapsed suspension unit. Early in 1968 in South Africa he overtook Fangio's record of 24 grand prix wins. He was among the greatest drivers of all time and the demands on his own time and talent were huge. There was the testing not only for Formula One but Formula Two and Indy cars. In a Formula Two race in Barcelona early in the season he was rammed by Jacky Ickx's Ferrari but the car was needed in Hockenheim the following week and there was little time to strip it down.
Quite why Clark decided to drive in a comparatively unimportant Formula Two race at Hockenheim on Sunday 7 April was a mystery to most people. He had been invited to drive in the British round of the world sportscar championship at Brands Hatch, but there were various contracts to which he felt it was necessary to adhere. He had never driven at Hockenheim and instantly disliked the circuit with its long straights. For him it seemed unnecessarily dangerous, and it was difficult to set up the car because as well as fast straights there were several twists and turns.
Driving a Lotus 48, he was sixth on the fifth lap and had no chance of winning. Rain had fallen, and the surface became wet. On a straight lined with trees and without barriers, Clark's car twitched. He corrected, but on a long curve and with his foot probably nearly to the floor, he must have realised that something was wrong. Clark was seen wrestling from lock to lock but the car slewed into the trees. There was no barrier and even the fairly advanced monocoque structure could not save him. He died instantly, but the mystery lived on. In another link with Senna, there was talk of steering failure, but the car was damaged beyond definitive investigation.
One of the mechanics suggested that there had been a slow puncture in the right rear and that the tyre collapsed under pressure from downforces as the car leaned into the curve. Clark may well have misread the twitching as being the result of oil on the track. Later in Britain Michael Aspel had only got as far as "The British driver Jim Clark..." and the nation knew that the unassuming and popular champion was dead.
Colin Chapman, the head of Lotus, seemed as confident that there was no mechanical failure as has been Frank Williams of Senna's car. An inquiry supported him but in another strange omen of Senna's crash, there was no clear photographic evidence of the moment when Clark's car began to go out of control. Just as with Senna, there were rumours of the throttles jamming. Extensive scrutiny of a tyre suggested that it was distorted before the crash and caused Clark to oversteer. There was nothing to intimate a mistake by a meticulous driver whose death would almost certainly have been avoided had the authorities at the time realised the need for barriers. Motor racing will never be safe, but Clark's avoidable sacrifice made its organisers begin to come to terms with their own negligence.