Signpost to Murder

When Roy's wife was found drowned in the bath he was accused of her murder. He was found guilty but insane and has been put in an asylum. Roy maintains that he is innocent and sane. He learns that if you escape from the asylum and stay undiscovered for twentyeight days you can have a retrial. He escapes and breaks into the cottage of a young married woman, Sally. She agrees to hide him. A few days later when Roy goes into the bathroom he discovers there is a dead man in the bath. He faints. When he recovers there is no longer a body in the bath. Is he really insane? Where is the body? And just who was the body - if there was one?