Based on an "actual event" that took place in 1943. About a US Navy Destroyer Escort that disappeared from the Philadelphia Naval Shipyard, and sent two men 40 years into the future to 1984.
It is several years after the events of the first movie, and David Herdeg (the survivor of the Philadelphia Experiment from the first film) and Allison (the woman from 1984 he fell in love with) have married and have a child. David awakes, in agony, to a changed world. Germany won World War II and the United States is now about to mark 50 years as a Nazi conquest.
Scotty moves into Mrs. Engels' seaside mansion where three other college students are boarding. Mrs. Engels prefers to stay in her room in the attic, but her son Mason helps the students get settled. Soon one of the students is killed. The policemen on the case begin uncovering the Engels family secret as the remaining students become endangered
