In the summer of 1914, he had headed to France in the company of his only son, Alistair. They were driving at high speed through woodland in Northern France when Alistair lost control of the wheel. The car spun into a roadside tree and flipped upside down. Alistair was flung from the vehicle and landed on his head. Cumming was trapped by his leg in a tangle of smouldering metal. ‘The boy was fatally injured,’ wrote Compton Mackenzie in his account of the incident, ‘and his father, hearing him moan something about the cold, tried to extricate himself from the wreck of the car in order to put a coat over him; but struggle as he might, he could not free his smashed leg.’ If he was to have any hope of reaching his son, there was only one thing to do. He reached for his pocket knife and hacked away at his mangled limb ‘until he had cut it off, after which he had crawled over to the son and spread a coat over him.’ Nine hours later, Cumming was found lying unconscious next to his son’s dead body. His recovery was as remarkable as his survival. He was back at his desk within a month, brushing aside any outer shows of mourning for his son. Cumming had the ramrod emotional backbone that so typified the gentlemen of his social class and era. Just a few months after his accident, one of his operatives visited him at his offices on the top floor of Whitehall Court. Cumming, who had not yet received his artificial leg, was inching his substantial frame down six flights of stairs: ‘two sticks, and backside, edging its way down one step at a time.’ Little wonder that his friends described him as ‘obstinate as a mule.