Exercise Hoodwink

Two Granchester constables find a wrecked, blood-soaked car. But there's no one in it, and no one has turned up at the nearest village. Then, miles away, a body is found on the road. A patrolman on night duty opens an unlocked door at the shop of a dealer in gemstones, a man named White. The police want to talk to White. Meanwhile, White has talked to mobster Dixie Costello. White's safe has been broken into, and diamonds are missing, but he hasn't told the police what has been taken.
Granchester Police will need every strategy they can think of to trap their man ...