Two Plumber offspring are taking down all aliens. Now they have their sites set on Ben's team, forcing the team to fight two of Ben's old alien forms - Four Arms and XLR8.

When an alien emperor deems to destroy Earth due to the disappearance of his daughter, Ben must use Alien X to restore order, but not everything goes according to plan.

The team is confronted by a Plumber Magister who accuses them of impersonating Plumbers. Meanwhile, a new foe allies himself with a HighBreed commander.