An alien phenomena of unprecedented size an strength, called V'ger, is on it's way to earth. It destroys every thing on it's path. The only spaceship that is in the vicinity is the Enterprise, which just got it's first major overhaul. While Captain Decker is preparing his ship to fight the danger, his legendary predecessor, admiral James T. Kirk arrives at the Enterprise to take command of the ship. Together with the original crew, Kirk and Decker are starting a dangerous mission to save earth.