Hatch Harrison, his wife, Lindsey, and their daughter, Regina, are enjoying a pleasant drive when a car crash leaves wife and daughter unharmed but kills Hatch. However, an ingenious doctor, Jonas Nyebern, manages to revive Hatch after two lifeless hours. But Hatch does not come back unchanged. He begins to suffer horrible visions of murder -- only to find out the visions are the sights of a serial killer.

After winning $6.2 million in the 1976 New York State Lottery, he is arrested for throwing rocks at a church. He then tells his story at the police station.

In an effort to find an economic means of purifying salt water, a joint U.S.-Japanese military command is set up on an isolated Japanese island where an unusual salt water lake is situated. However, their purifying experiments arouse the prehistoric monster Obaki from hibernation at the lake's bottom, and it proceeds to attack Japan. Although made by a U.S. independent film company, this film was based on a Japanese Toho monster film of 1958, "Daikaiju Varan", from which all of the monster effects scenes and a few incidental dramatic shots were edited into it.