Jack, Trip, and Mike have brought the fight to the Whistlers' terrifying homeworld. With the help of some unexpected allies, the men must finally find a way to stop the enemy before they [come] through the planes of existence to destroy all life. What they don't know, what they can't know, is that there is much more to the enemy than they previously thought, and defeating them may be an impossible task. Will our heroes be able to stop the enormous war machine and return home, or will they perish in the attempt?