Designer David Starling, who returned from a business trip, caught his wife Celia having an affair with her sister's fiance. Celia was shot that night, and David was charged with first-degree murder as the only person present. Although David's daughter Susan witnessed the crime scene, she was mentally disturbed by stimulation and refused to communicate with others. Caroline Canford, a child psychiatrist, tried her best to save the suffering little girl, only to discover an amazing truth in the process-who is the shadow on the wall?