The Musgrave Ritual (Easy Classics)

Reginald Musgrave, who knew Holmes at university, hires him to investigate the disappearance of his butler Richard Brunton and his maid Rachel Howells. The butler disappeared shortly after he was found reading a copy of the Musgrave Ritual, a series of questions and answers that members of the Musgrave family have long recited when they reach adulthood but which are generally considered to be meaningless. Holmes deduces that Brunton discovered the hidden meaning behind the Musgrave Ritual and that, if he can do the same, he will solve the mystery of the two servants' disappearance.