Edward Grainger is a student at Denby prep school. He is bullied by two older students, Digby and Lillis, who haven't actually hurt him (yet), but he is terrified of them. The Doctor has escaped his pursuers, or so he thinks, and finds himself in England in the middle of nowhere. A man in a car, giving his name as Marcus Johns and saying he is a physics master, offers the Doctor a ride. They have a flat tire, and when Johns gets out of the car to fix it, he starts to push the car off a cliff. The Doctor escapes in time, realising that his pursuers have acquired the ability to shape shift.