Ben is supposed to attend a tournament to support his girlfriend, but the Forever Knights are trying to break into a museum. Ben tries to use the Ultimatrix to handle all his obligations.
With Ben's identity known, some of his enemies (such as Zombozo, Rojo, Charmcaster, Vulkanus, and SevenSeven) team up to try to attack his family. Now Ben and friends have to protect them no matter what.
Ra'ad, the last of Aggregor's escaped prisoners, attacks Ben and informs the team of the true fate of his comrades. He finds a safe hiding place but one that endangers Ben in the process.
Aggregor has all five aliens. The Plumbers manage to disable Aggregor's ship, forcing Aggregor to find a new way to absorb their powers. The team makes a last ditch effort to save the alien prisoners.
Aggregor escapes to a magical dimension. Gwen asks for Charmcaster's help to pursue him. The team learns about Charmcaster's past and why she's willing to help them now.
As the team makes its final attempt to stop Aggregor, they find an unexpected ally, and one person will make a fateful decision with lasting repercussions.
Kevin's out for payback on anyone who has ever crossed him. His next stop is a prison in the Null Void. Ben and Gwen try to stop him, where Ben comes to a grim decision.
Kevin starts going after Plumbers kids to gain more power. Ben and Gwen continue to argue about how to handle the situation. Gwen tries to find someone who will help her cure Kevin.