Book excerpt: Jimmy Answell is summoned for an audience with Avory Hume. The two men are later discovered after witnesses break into Hume's study - a room with bolted steel shutters and a heavy door locked on the inside. Answell is found lying unconscious and Hume stabbed to death with an arrow. How can young Answell not be guilty? Sir Henry Merrivale investigates and reconstructs the crime in the courtroom.