The date is 1956, Aintree, and Dick Francis is riding the Queen Mother's horse to victory in the Grand National. Except Devon Loch collapses bizarrely to the ground within sight of the finishing post. The jockey later says that he never recovered from this defeat. But the strange case of Devon Loch and the most famous Grand National of them all is the making of Dick Francis, who becomes both a household name and a best selling author too.

Martin Broughton, chairman of British Airways, the British Horse Racing Board and - for a while - Liverpool FC, chooses Dick Francis as his example of a man who succeeded in two careers. The Francis novels have sold in millions. Philip Larkin loved the opening lines: "There was a godawful cock up in Bologna," begins The Danger.

But there have been question marks over whether the books were all his own work. Mischievous biographer Graham Lord tells Miles Warde why he thinks Dick's wife, Mary, was responsible. "Garbage," says Martin Broughton. Expert opinion comes from Jonathan Powell, racing correspondent of the Mail on Sunday and a man who knew Dick Francis in his later years. The presenter is Matthew Parris, the producer Miles Warde.