During an excavation of human artifacts, Finn, Jake and Susan Strong (voiced by Jackie Buscarino) are greeted by a mysterious new stranger named Dr. Gross (voiced by Lennon Parham) who lives in a subterranean ship. This enigmatic figure believes that nature can be "upgraded" via cybernetics. At first hospitable, Dr. Gross turns violent and antagonistic when Finn, Jake, and Susan decline to be upgraded. During the course of the episode, Dr. Gross discovers Susan's cybernetic implant, but is unable to activate it before her ship is destroyed.