It is the summer of 1894. The Garry Street murder is the talk of London, and no one is more baffled than Gerald Conway, in whose library the dead man's body was discovered, stabbed. The only clue to the man's identity seems to be the gold bangle containing a small carbuncle, worn on the dead man's left wrist. Soon Conway finds himself accused of murdering a man he has never met. Luckily for him, however, his old friend Octavius Rixton (alias Octavius Fanks, detective) is on the case!