When the Battleship Missouri blasts into orbit, Space Marine Sergeant Zack Delano (Billy Worth) and Captain Tom Gray (Edward Albert) are launched into the most dangerous space mission in history.

The time is the mid 21st century and the Universe is governed by a powerful, peace-loving organisation: The United Planets. Space Marines are the highly trained elite special forces deployed by the United Planets to maintain order. Peace has been broken by a band of renegade space pirates, led by the sadistic Colonel Fraser. They have hijacked an intergalactic nuclear cargo ship and have kidnapped a high-ranking United Planets official in the process. The spectacular confrontation that ensues will determine the future of the free planets...