Ben 10: Ultimate Alien Episode 2.01 The Transmogrification of Eunice

Ben, Gwen, and Kevin go out into the wilderness for a camping trip. During a car race between Ben and Kevin, a strange pod falls from space. While trying to open the pod, Gwen cuts her hand on it. The pod then opens to reveal a naked blonde girl. Gwen gives the girl some of her spare clothes and the girl reveals her name to be Eunice, though she doesn't remember anything else. As the camping trip continues Eunice is revealed to have a strange connection to nature and Ben begins to have romantic feelings for Eunice (Note: Julie broke up with Ben between Seasons 1 and 2). Sunder then arrives on Earth on a mission to find Eunice. While Ben tries to take Eunice to see the ravine, Sunder appears and Ben and Eunice are separated. Ben, Gwen, and Kevin find Eunice at the ravine where Sunder activates a button on her neck, which turns her into a cylinder-like device. Ben stops Sunder from escaping with Eunice and Kevin returns Eunice back to her human form. As Eunice interrogates Sunder about her past, Azmuth appears and tells them that Eunice is really one of his early prototypes of the Omnitrix, known as the Unitrix, and that Sunder was freed from the Null Void by him to retrieve the Unitrix for him. Ben convinces Azmuth to not put Eunice into storage but to instead put her on Primus. Before she leaves with Azmuth and Sunder, Eunice gives Ben a blue flower as thanks for helping her.