George goes fishing at a quiet isolated lake one morning. He is suddenly attacked and pulled into the water, screaming for help. He is later found unconscious on the shore with cuts and bruising. At his home, George and his wife watch a news report about a man being attacked at the lake. George realizes with shock that the injured man is himself, as he has similar injuries, but cannot remember what happened. The police investigate the mysterious crime at the lake but have no further information.