Analogies between readers and detectives are not uncommon in reader-response criticism, but few works in the genre lend themselves so comfortably to that approach as Margery Allingham's Traitor's Purse does. We read crime fiction at least partly to test our wits, perceptions and puzzle-solving abilities with and against the ultimate reader-in-the-text and decipherer of signs, the detective. Often, curiously enough, part of the pleasure comes from recognising a (fictional) intelligence superior to our own, but this is not the case with Traitor's Purse or Allingham's Hide My Eyes.¹