Sam has to do a postmortem on the body of Stuart Evans, who was found dead the morning after his party. He was terminally ill with an AIDS related illness, but Sam finds a suspicious needle track in his foot and is convinced he has been murdered.

Sam is called to the scene of a woman found strangled with her own tights. Superintendent Peter Ross believes that it is connected to an old unsolved case, but Sam is not so sure. The dead woman was suspected of having an affair with Alan Whyte, and soon his body is also found.