Based on a famous play, follows a bedridden wife who overhears a murder plan on her phone. She tries to piece the puzzle together and prevent it.

A patient being psychoanalyzed by Dr. Snow is a government scientist. General Pratt hides him in a secret place known as "Base X," forcing Dr. Snow to wear a blindfold whenever he is taken there ...

Leona Stevenson is confined to bed and uses her telephone to keep in contact with the outside world. One day she overhears a murder plot on the telephone and is desperate to find out who is the intended victim.