When two robbers try to rob a gas station mart, Ben decides to turn into Four Arms to stop them. However, when he tries to activate the Omnitrix, it seems to be missing from his wrist. To make the situation more confusing, Grandpa Max and Gwen seem to have no knowledge of the summer they've spent together so far. It turns out that it's the first day of their vacation. Ben discovers that he has traveled back in time, and he decides to get the Omnitrix again. When he arrives at the crash, though, Gwen was able to get there first and obtain the device. Gwen has more control over the Omnitrix than Ben did. Can Ben find a way out of this alternate reality, and get things back the way they were?
Elenco: Ashley Johnson , Charlie Schlatter , Dwight Schultz , Greg Cipes , Greg Ellis , Jeff Bennett , Jim Ward , John DiMaggio , Kevin Conroy , Kevin Michael Richardson , Michael Dorn , Peter Renaday , Richard Green , Rob Paulsen , Robin Atkin Downes , Tom Kane , Vicki Lewis , Yuri Lowenthal , Jennifer Hale , Kari Wahlgren , Khary Payton , Tara Strong , Claudia Schmidt , Meagan Smith , Paul Eiding , Ulf Söhmisch , Dee Bradley Baker , Fred Tatasciore , Richard McGonagle , Richard Steven Horvitz .