Ben returns home after summer vacation ends and is told that he must keep the Omnitrix a secret.
This is made all the more difficult by Ben's classmates who admire Ben's alien heroes while completely oblivious to Ben being them. Initially disappointed, Ben gets the chance to use the Omnitrix when Vilgax attacks, looking to take the Omnitrix from Ben. All four Tennysons (Ben's father helps) fight off Vilgax's drones running amok in the city. When Vilgax appears again, easily fending off Ben, Ben's father suggests leading him into the underground gas line, which they ignite to incinerate the villain. Ben's secret is revealed to the public and Gwen ends up transferring to his school. Just when it seems like everything is quiet, Dr. Animo shows up with a mob of mutated animals, which Ben and Gwen get ready to fight.
If you listen closely in the scene when the kids run from Vilgax's robots in the gym, one kid sounds like Cooper screaming.
Many of Ben's alien exploits are mentioned by Ben's classmates, such as Heatblast's burning building rescue (Washington B.C.), Four Arms' fight with Kevin on top the Golden Gate bridge (Framed), Wildmutt's battle with Hex in Las Vegas (Tough Luck), Wildvine's battle with Sublimino (Midnight Madness), and Diamondhead at the Little League World Series (The Unnaturals).