The film centers on a group of Navy SEALs, led by United States Dr. Frank Reno (Michael Gross (actor)), who once worked on the Philadelphia Experiment. The film begins in 1998, when Reno has purportedly perfected time travel technology. The SEALs use it to travel backwards to the year 112,000,000 BC (despite the movie's title) of the Early Cretaceous, in order to rescue a previous, 1949 expedition led by Reno's brother Erik (Christopher Atkins).