Back in the TARDIS Adric is writing on a pad of paper. DOCTOR: 26th century. DOCTOR: Earth. Scott garbs him by the shoulders. The Doctor, Tegan and Nyssa move into the cavern where the troopers are "hiding".
Plan: A: The Doctor; Q: Who lands the Tardis in an underground cavern on 26th century Earth? A: Tegan; Q: Who is the Doctor's companion in this episode? A: Adric; Q: Who is the fourth member of the Doctor's team? A: the military; Q: Who is searching for the missing scientists? Summary: The Doctor lands the Tardis in an underground cavern on 26th century Earth. Then the Doctor, Tegan, Nyssa and Adric become embroiled in the search for a team of missing scientists being preformed by the military.