Lenore Davis and her husband Frank are about to have their second child. As she gives birth, the newborn baby vanishes and leaves behind five dead bodies. It's up to the police and Frank to figure out where their mutated child has gone.

A London cabby finds a greyhound puppy in his cab, and gives it to his daughter. She raises it and trains it up at the race tracks; and in spite of crooked rival owners, the dog eventually wins the Greyhound Derby.

Life becomes a tragedy for the wife of an Irish heir to a 19th-century family feud and fortune.