Door and Richard come face-to-face with the awe-inspiring Angel Islington while the Marquis de Carabas plays a deadly game with the merchants of violence Croup and Vandemar.

The Marquis is killed by the Messrs, and Islington instructs Door and Richard to retrieve a key from the Black Friars. Hunter passes a difficult test and Door a not so difficult one, but a third trial, the most difficult of the three, must be overcome by Richard if they are to be given the key.