The story takes place in 1894, three years after the apparent death of Sherlock Holmes. On the night of March 30, an apparently unsolvable locked-room murder takes place in London: the killing of the Honourable Ronald Adair, son of the Earl of Maynooth, a colonial governor in Australia. Adair was in his sitting room, working on accounts of some kind, as indicated by the papers and money found by police. He 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 in partnership with Colonel Sebastian Moran. The motive does not appear to be robbery as nothing has been stolen, and it seems that Adair had not an enemy in the world. It seems odd that Adair's door was locked from the inside. The only other way out was the open window, and there was a 20-foot (about 6 m) drop below it onto a flower bed, which shows no sign of being disturbed. Adair was killed with a soft-nosed revolver bullet to the head. No one in the area at the time heard a shot.