Wolf Rilla makes his directorial debut in this 1950s British crime thriller based on a novel by Gerald Verner. Simon Gale (Dennis Price) is shocked to discover on his return to Britain from a spell abroad that his beloved cousin Margaret (Pamela Alan) has been convicted of murder and is set to be executed in a week. Convinced that Margaret is innocent of the crime with which she has been charged - poisoning her husband - Simon embarks on an amateur investigation into the mysterious events. He finds an ally in Margaret's stepdaughter Jill (Rona Anderson) and the pair work together to identify the real killer. When Simon uncovers a second victim of poisoning, he believes his suspicions have been proved correct - but can he reveal the truth in time to save Margaret?