Oscar winning Jack Cardiff directs twisting British thriller in which a detective investigating the murder of a young woman makes a startling discovery. Veteran detective Matthews (James Booth) is determined to crack the brutal murder of a young woman. Her face has been badly battered but her body is identified by her identical twin, Delphi (Francesca Annis), towards whom Matthews feels a growing attraction. As Matthews' investigations take him deeper, he uncovers a plot to steal a priceless rare stamp involving the victim's sister. With twins, there is always one good ...and one bad.