Solve the riddle given by Liesl.

After Boy’s funeral, Dunstan attends Eisengrim's magic show. When the Brazen Head illusion begins, a distraught David Staunton asks who killed Boy Staunton. The head's cryptic answer references women Boy did and did not know. The head then adds that Boy was also killed, “by the inevitable fifth, who was the keeper of his conscience and keeper of the stone“ (266). He knows then that Paul killed Boy.

At this revelation, Dunstan suffers a heart attack. He eventually recovers, and receives a letter from Liesl inviting him to join the carnival in Switzerland.