Evelyn Henshaw is convinced that her husband is a murderer and is now plotting another death - her own. She pleads with solicitor Rosa Epton to inform the police should anything happen to her. When the weighted body of a young man is dredged from the lake at the Henshaw's home, Ralph Henshaw is called in for questioning. He begs Rosa to prepare his defence, but she finds herself ensnared by conflicting loyalties. Is her new client the victim of an elaborate trap or a killer?
