Sixteen-year-old Nelson Potter (Corey Haim) is part of a bank-robbing team with his father Sam Potter (Leo Rossi). Nelson scouts targets for the group and often acts as a hostage during their heists, while the lineup includes Tony Bush (Ken Lerner) and Lilly (Cynthia Rothrock), the latter a skilled martial artist and Sam's current love interest.
Wanting Sam all to herself, Lilly challenges the arrangement and tries to cut Nelson from the crew, but Sam refuses. After she overhears Sam insulting her, Lilly withholds Nelson's share and violently attacks Sam, forcing Nelson to subdue Lilly at gunpoint. With the partnership dissolved, Tony and Lilly leave the group.
Having stolen a new getaway car, Sam and Nelson press on solo. Sam's goal is to save enough money to pay for Nelson's college education, while Nelson sees nothing wrong with robbing banks for a living. During another Utah bank robbery, Tony and Lilly tip off the police from their hotel room across the street, and Sam is arrested. Nelson is deemed a runaway, and Lilly and Tony hurry to claim him at the police station, hoping to use him for fresh robberies.
However, a woman named Lorraine (Marcia Strassman) finds Nelson after learning about the attempted heist on television. She deftly evades Tony and Lilly in a high-speed chase and takes Nelson back to her home. Impressed with her driving skills, Nelson pleads for Lorraine's help in breaking his father out of jail. Lorraine reveals that she is Nelson's biological mother, having lied about her death for years so that Nelson would stay with Sam after their separation. Feeling betrayed, Nelson tells his father he can no longer trust him.
That night, Tony and Lilly track down Lorraine at her workplace and follow her back to her home, where they kidnap Nelson. Using Nelson's maps, atlas, and other resources, Sam and Lorraine deduce that his next target isn't a bank but the Salt Lake City Amphitheater. They race to confront Tony and Lilly, who have already robbed the venue by using Nelson as a hostage in a vest loaded with dynamite. After forcing Nelson into the back of their pickup truck at gunpoint, Tony and Lilly attempt to get away with Sam and Lorraine in hot pursuit.
In desperation, Lilly attacks Nelson and throws him from the truck, leaving him dragging precariously behind the vehicle on a strip of chain-link fence. With Lilly distracted by a police helicopter, Sam climbs aboard the moving truck and gets the upper hand against Lilly, knocking her onto the highway. He then forces Tony off the road, giving Nelson enough time to remove the bomb and plant it in the truck. While Sam reaches for the detonator, Tony attempts to run him over, but Lorraine rams into the truck with her car at the last second, sending it tumbling down a cliff where it explodes. As the three drive away to seek medical treatment for Nelson, Tony is shown dangling helplessly from the face of the cliff, having survived the ordeal.
Sometime later, Sam, Nelson, and Lorraine embark on a road trip to Canada, where they jokingly make plans for their next bank robbery.
