Faced with the looming threat of an alien invasion, Gwen manages to persuade Ben to come out of retirement and join the resistance. However, he must convince his past self to also lend a hand.
When Ben meets a young Generator Rex on the run from a hostile Providence, he must work through a series of misunderstandings, and defeat the dark wizard Hex in order to save the world.
When the Tennysons are attacked by a villainous, dimension-hopping Omni-alien known only as Alien X, they soon meet a parallel universe version of Max who opens the door to hosting multiple Bens and Gwens, forming an alien hero army to combat this threat.
