When the body of a girl is found, cut into three, Detective Inspector Edgar Stephens is reminded of a magic trick, the Zig Zag Girl.

The inventor of the trick, Max Mephisto, is an old friend of Edgar's. They served together in the war as part of a shadowy unit called the Magic Men.

Max is still on the circuit, touring seaside towns in the company of ventriloquists, sword-swallowers and dancing girls. Changing times mean that variety is not what it once was, yet Max is reluctant to leave this world to help Edgar investigate. But when the dead girl turns out to be known to him, Max changes his mind.

Another death, another magic trick: Edgar and Max become convinced that the answer to the murders lies in their army days. When Edgar receives a letter warning of another 'trick', the Wolf Trap, he knows that they are all in the killer's sights...