(Before them, the DOCTOR and SUSAN stare at the monitor from the control console. (He wanders off, a troubled look on his face as the other three huddle near the TARDIS.) (She calls.) BARBARA: They're so sure, Ian...
IAN: Yes, I know...
BARBARA: And remember the difference between the outside of the police box and the inside...
IAN: Yes, I know, but... (To the Doctor.) Doctor who? HUR: (By Za.) He places the DOCTOR on a large rock. However, we can go out now. In his hands! Incredible - a police box in the midst of...it just doesn't make sense...
(SUSAN looks at the TARDIS, and is surprised herself to see that it's still a police box.) Kill her! Leaving this? My strength was too much for him! SUSAN: Grandfather! Sand and rock? They don't understand, and I suspect they don't want to. Where are they? ZA: Take them to the Cave of Skulls. ZA: When Orb decides it!
Plan: A: two humble teachers; Q: What were Barbara Wright and Ian Chesterton? A: 1963; Q: What year did Barbara Wright and Ian Chesterton meet Susan Foreman? A: a bright student; Q: What kind of student is Susan? A: her upbringing; Q: What do Barbara and Ian want to know about Susan? A: a junkyard; Q: What do Barbara and Ian find when they go to Susan's home? A: her grandfather; Q: Who is Susan Foreman's guardian? A: his and Susan's otherworldly origins; Q: What do the teachers know too much about? A: his TARDIS; Q: What does the Doctor use to travel through space and time? Summary: Barbara Wright and Ian Chesterton, two humble teachers during 1963, are surprised by a bright student named Susan Foreman. Feeling inquisitive of her upbringing, they seek out her residence to learn who nurtured such a genius. There, they discover a junkyard inhabited by her grandfather, simply known as "the Doctor", and he doesn't want them lurking about. When the teachers refuse to leave, they discover that an ordinary police box is actually bigger on the inside. The Doctor decides they know too much about his and Susan's otherworldly origins and takes them on a journey across space and time in his TARDIS, the place he and Susan now call home.