Until LAPD Detective Milo Sturgis and psychologist Alex Delaware are called to the scene of a bizarre crime. A stolen car has been anonymously returned to its owner, undamaged and unblemished - except for a tiny, solitary bloodstain. This minuscule clue is enough to set the pair on a hunt for a multiple killer, from the well-heeled centre of LA society to its desperate edges, even as far as New York, where their search thaws out a long-cold case. However, this killer proves to be a fleeting shape-shifter, defying identification - and to unmask him, Alex and Milo will have to confront the true face of murderous compulsion ...