The story itself begins, typically enough, with a murder - the Park Lane Mystery, the seemingly motiveless killing of Mr. Ronald Adair, son of a high colonial official. The authorities, not to mention the man's family, are perplexed by the case: it seems that the Honourable Ronald Adair hadn't an enemy in the world. He was in his sitting room, with a window open, working on accounts of some kind, as indicated by the papers and money found by police. Ronald liked playing whist and regularly did so at several clubs, but never for great sums of money. It does, however, come out that he won as much as 420 Pounds in partnership with a Colonel Moran.