An alien race asks the team to deliver the Tiffin to another race as a peace offering. The Omnitrix changes Ben into a new form that's highly aggressive, which causes other problems on their peace mission.

Despite being warned by Paradox, Gwen travels back in time to prevent the accident that turned Kevin into a monster from ever happening. Gwen returns to the present only to find that her time traveling caused a series of events that led to Hex ruling the world.