A hitch-hiker dressed in yellow oil skins attacks the driver of a car who has stopped to give him a lift. The car crashes and the driver fights with the insane hitch-hiker. It appears like the driver, though badly injured, has prevailed and is taken to hospital. The drivers wife subsequently learns that her husband has damaged his throat in the struggle and is unable to talk, she is also asked to identify the body of the madman. The body looks exactly like her husband and doubts begin to enter her mind as to which of the two is the killer. The only differences appear to be that the killer has rotten teeth and a claw-like finger nail. Who survived the fight her husband or the madman?