The Judas window (1938)

A defendant seems trapped by the evidence after waking in a locked study beside a man killed with an arrow. Sir Henry Merrivale's courtroom defence turns the facts into propositions that can be challenged in public. Follow what each witness can actually establish and keep the room's layout in mind. The legal contest makes this a particularly approachable route into a tightly bounded impossible crime. Carter Dickson is John Dickson Carr's pen name.