Summer's over and Ben is back at school. Unable to tell anyone that's he all these cool aliens that they've heard about all summer, Ben suddenly realizes he's gone from a "hero" to a "zero", that is until Vilgax comes after him with a vengeance. Ben must now reveal his hero side to his parents and to his fellow classmates. In doing so he saves his town and teams up with his dad to destroy Vilgax once and for all. But there is some bad news...Gwen has switched schools and is in Ben's class!