Nine months after the death of Anne Kneilands, the police are no further forward in finding her killer, although Detective William Muncie is sure he knows the culprit. Even though not part of the investigation, he goes to Peter Manuel's home to try and reason with his father who gave him the alibi he needed to be free from police suspicion. Then Muncie hears the news that three women in the Watt family have been shot dead in their beds. The husband William, who was on a fishing trip at the time, is arrested. However, Muncie is convinced Manuel is the man behind all four murders.