A massive alien spacecraft of enormous power is approaching Earth, destroying everything in its path. The only star ship in range is the USS Enterprise still in dry-dock after a major overhaul. As Captain Willard Decker readies his ship and his crew to face this menace, Admiral James T. Kirk arrives with orders to take command of the Enterprise and intercept the alien intruder. But it has been three years since Kirk last commanded the Enterprise on its historic five year mission... is he up to the task of saving the Earth?