No Ordinary Family S1 Ep 13 - F2F Transformations

Season 1 Episode 13 No Ordinary Detention
Katie comes up behind him and warns that they can't go anywhere, and the Watcher insists that he won't go back to the lab. She starts to kiss him, and the Watcher realizes it's not Katie. "Katie" steps back and transforms into Victoria, who admits she knocked Katie out. Katie returns to the lab and explains that someone knocked her out. "Katie" comes in and they realize that there's a shapeshifter involved. "Katie" suggests that Stephanie quiz them, and Katie admits that it's a reliable method. However, Victoria has studied Katie's files. When they keep coming up with the same answers, Stephanie asks them what the real Katie did for the first time a week ago. The real Katie hesitates to tell her in public, and finally whispers that she had sex for the first time.