One of Those Things is a 1949 thriller novel by the British writer Peter Cheyney.^[1] Although best known for his series featuring Lemmy Caution and Slim Callaghan, this was one of several stand-alone novels he wrote featuring hardboiled private detectives. It was also published under the alternative title Mistress Murder.

Irish private eye Terence O’Day attends the Plumpton Races picking up tips about both a horse and a woman, the attractive but treacherous Merys Vanner.