Arnold Bourdon has a domineering wife named Elizabeth. When Elizabeth takes ill, she hires a lovely nurse named Joan. Arnold grows close to Joan, but she refuses to continue the affair as long as Arnold is married. The two plot to give Elizabeth a fatal doses of medication. Unfortunately, Elizabeth sees Joan kissing Arnold and fires her. Later Elizabeth hires another nurse. This one is an old woman in her sixties. Arnold asks the new nurse about Liz's medicine. The new nurse tells him that she will give her more medicine that the doctor recommended. Arnold, knowing that the dose will prove fatal, thanks the nurse and in his thanks reveals that she is his mother.