When a naked body is found in a room in a prestigious hotel in Edinburgh, and nothing is known about him except his name because his registration document has been stolen, DCI Ian Forsyth and DS Alistair MacRae are at a loss to know how to proceed until they learn that he had made arrangements to visit four forms involved in an export drive organised by Councillor Benson. When the head of one of the firms is also murdered, the pair are convinced that the killer suffered from a knife wound inflicted by the victim, but examination of all the suspects fails to reveal such a wound. After a disastrous attempt by the squad to root out the killer leads to a further death, Forsyth applies logical deduction to interpret a clue left at he scene by the victim, is able to explain the failure to find the knife wound and brings the case to a successful conclusion