De Forest Kelley, most famous for his role as Dr McCoy in Star Trek, makes his feature film debut as bank teller Vince Grayson. Vince dreams that he is in a mirrored room accompanied by a blonde who is robbing a safe. Vince and a man fight and he kills the man and places the body behind a mirrored door. When he wakes he has a key in his pocket and bruises on his body. Is he a killer? He visits his brother-in-law, homocide detective Cliff Herlihy (Paul Kelly) who thinks Vince is merely under stress and organises a day trip with Lil Herlihy (Ann Doran) and Betty Winters (Kay Scott). As they picnic, a storm forces them to shelter in a house that contains a mirrored room... Is this a set up? Is Vince a killer? Vince has flashbacks and nightmare with many twists and turns leading to an exciting car chase.