How do you stop a murderer who can't be seen? He appeared as if from nowhere, brutally slashed a man and a young woman in an office elevator, then vanished again without a trace. The woman survived and gave the police a detailed description of the killer's bizarre face, yet the police can find no sign of him anywhere. It's as if he never existed. But now he's killed again. And again. One woman holds the key to his terrifying secret... but how do you stop a murderer who isn't there? 'One of the most original and frightening storytellers of our time' PETER JAMES. 'A true master of horror' JAMES HERBERT.