In this suspenseful sci-fi thriller, cab driver Jeff Wilder (Scott Bakula) witnesses a spectacular traffic accident involving a NASA van. While rescuing the injured driver, Wilder is exposed to a mysterious gas escaping from a space cannister within the overturned vehicle. Suddenly he is transformed into a virtually "indestructible" human being - I-Man. Before long, Wilder becomes the U.S. Government's secret weapon in stopping a power-hungry maniac (John Anderson) who has hijacked a military train and is threatening the world with the ultimate disaster: nuclear meltdown.