- Romana: Newton? Who's Newton?
- Doctor Who: Old Issac? Friend of mine on Earth. Discovered gravity. Well, I say he discovered gravity; I had to give him a bit of a prod.
- Romana: What did you do?
- Doctor Who: Climbed up a tree.
- Romana: And?
- Doctor Who: Dropped an apple on his head.
- Romana: Ah. And so he discovered gravity.
- Doctor Who: No-no, he told me to clear off out of his tree. I explained it to him afterwards at dinner.
- Mr. Fibuli: The psychic interference transmitter, sir. There seems to be something counter-jamming it.
- Captain: What? We dematerialize in three minutes!
- Captain: [activating the P.A. system] All guards on alert! Someone is using a counter-jamming frequency projector! Find it and destroy it immediately!
- Mr. Fibuli: Captain, do you suppose any of the guards know what a counter-jamming frequency projector looks like?
- [the Captain considers for a moment, then...]
- Captain: [into the P.A. system] Destroy everything!
- Doctor Who: Switch off the TARDIS forcefield.
- Romana: What? But that's madness. It's the only protection we've got!
- Doctor Who: I know. Do it!
- Romana: It's been nice knowing you, Doctor.
- Doctor Who: And you.
- Romana: Calufrax...
- Doctor Who: ...is not a normal planet. It's an artificially metricised structure consisting of a substance with a variable atomic weight.
- Romana: We can't move anything in here. If we do, we'll just upset the whole system and create a gravity whirlpool.
- Doctor Who: Not if I do something immensely cleaver.
- Romana: What about the bridge and the Time Dams?
- Doctor Who: Bridge and time... K9!
- K9: Piece of cake, Master. Blow them up.
- Romana: Oh, isn't that rather crude?
- Doctor Who: Well... it's a bit crude but immensely satisfying.