Harold lives with his invalid mother and feels trapped by her. After getting drunk for the first time ever he awakes in the morning to find his mother strangled. He is an immediate suspect, but he knows he is innocent. But, as the suspicion shifts to others, he becomes less certain. He confesses to a call girl he patronizes and trusts. She convinces him the killer is someone else by pointing out a detail he had not previously considered. After lulling him into a false sense of relief, she betrays him to the police. He spends a night in jail and in the morning the crime is solved with a surprise denouement.