When Simon Serrailler was a rookie constable with the Met, he did something reckless in the course of a night's work which caused a man's death. But his act was praised by his colleagues and he was called a hero.

Years later, now a Detective Chief Superintendent who has been badly injured in the course of duty, he receives a medal for bravery at Buckingham Palace, while recollecting that fateful night of his early career, when chance disguised itself as bravery.