Bank teller Vince Grayson (DeForest Kelley) wakes from a nightmare in which he and an unknown woman murdered a man in a mirrored room. Only a dream but Vince finds he has physical objects and bruises from his "dream." His cop brother-in-law dismisses his story until the family, on a picnic, takes shelter from a thunderstorm in a deserted mansion containing the mirrored room.
