Bill Slider and his team face a mystery when an unidentifiable man appears to have committed suicide but all signs point to murder. A young man is found dead in his bath, exsanguinated. Bill Slider's colleague takes one look at the body and is convinced something isn't quite right. As they try to identify the man - whose personal papers are missing, along with his wallet and keys - it seems that the more they find out about him, the less they really know.