- Brig. Alastair Gordon Lethbridge-Stewart: I think the general's a bit overwrought.
- Prof. Ralph Cornish: I think he's insane.
- Dr. Liz Shaw: General Carrington!
- General Carrington: Miss Shaw!
- Dr. Liz Shaw: How on earth did you find us?
- Doctor Who: I think the General knew all along.
- General Carrington: You're not surprised to see me?
- Doctor Who: Not particularly, no.
- General Carrington: I'm surprised to see you, Doctor. My instructions were that you were to be killed!
- Doctor Who: Well, somebody disobeyed your instructions. Didn't they?
- General Carrington: I'll have to attend to the matter myself. I'm sorry, Doctor, it's my moral duty.
- [first lines]
- Control Room Assistant: Large unidentified object converting with Mars Probe 7 on collision course. Estimated speed seven thousand miles per hour, but decreasing.
- Prof. Ralph Cornish: Doctor, a large unidentified object is approaching you on collision course. Take evasive action.