- Tegan Jovanka: You could go back!
- [the Doctor looks up from the console at her, shocked by the outlandish suggestion tempered with an understanding of why]
- Nyssa: Could you?
- The Doctor: [firmly] No.
- Nyssa: Surely the TARDIS is quite capable of...
- Tegan Jovanka: We can change what happened if we materialise before Adric was killed!
- The Doctor: And change your own history?
- Tegan Jovanka: Look, the freighter could still crash into Earth, that doesn't have to be changed. Only Adric doesn't have to be on board.
- The Doctor: [angrily] Now listen to me, both of you: there are some rules that cannot be broken, even with the TARDIS!
- Nyssa: Doctor...
- The Doctor: Don't *ever* ask me to do *anything* like that again! You must accept that Adric is dead. His life wasn't wasted, he- he died trying to save others, just like his brother, Varsh.
- Tegan Jovanka: That's not Hyde Park. That's Heathrow Airport!
- The Doctor: You're right.
- Tegan Jovanka: Well, I never thought I'd say this, but let's get out of here: We could be in the path of an oncoming aircraft.
- Andrews: [standing near the TARDIS in the midst of Terminal One] Are you responsible for this box, sir?
- The Doctor: Well... I try to be.
- Nyssa: Doctor, you've done it again.
- Sheard: Are you saying you know where the missing aircraft is?
- The Doctor: I suspect it's not a question of where but, uh, when.
- Captain Stapley: You seriously believe that Victor Foxtrot got caught in some sort of time-slip?
- The Doctor: It would seem to be the logical explanation.
- Captain Stapley: That's pretty rum idea to me.
- The Doctor: [regarding the cargo hold of the airplane] It's amazing.
- Nyssa: What?
- The Doctor: This thing's smaller on the inside than it is on the outside.
- The Doctor: Behind every illusion there's a conjurer. In this case I shouldn't think he went to all this trouble for our entertainment.
- The Doctor: Definitely Jurassic. There's a nip in the air, though... we can't be far off the Pleistocene Era.
- Tegan Jovanka: The ice age?
- The Doctor: It's times like this I wish I still had my scarf.