The Visitor

Two snowmobilers accidentally release an alien named Xylene from a strange container. Xylene locates the Omnitrix and attacks Ben, under the impression that he had stolen it. However, when Max comes to defend, the two recognize each other as old friends. Xylene and Max reminisce later that night. As Wildvine spies on them, Xylene asks Max to leave Earth and travel through the Universe with her. Distraught, Ben runs back to the campsite, where he is unable to ward off an attack by one of Vilgax's remaining drones and has to rely on Max and Xylene for help. There, Xylene reveals that she was the commander of the ship bringing the Omnitrix to Earth when Vilgax attacked it, and that she had intended to send it to Max; Ben received the Omnitrix by accident. Ben runs off in shock and Gwen follows. The drone attacks again and captures Max. Ben and Xylene reluctantly team up to save him. In the process, Xylene uses her knowledge of the Omnitrix to unlock a new form, Upchuck, which Ben uses to destroy the robot. At that, Xylene prepares to leave the planet and repeats her offer to Max. Max declines, claiming that Ben and Gwen are his whole world.