Kathleen and Bettie are tricked by their nerdy step-brother into participating in his science project. He tells them that he invented two robot conversion devices. They of course don't believe him, and think the devices to be harmless. But after just a few moments in their respective devices, the conversion process begins and both girls' minds go blank and empty. They're no longer laughing at their step-brother, but instead obeying his every command. Topless, nude down to panties.