- [as the Cybermen are softening a bridge door]
- The Doctor: [to Adric] What is the square root of 3.69873?
- Adric: About 1.92321.
- [the Doctor enters it into the freighter's computer and 1.923208 appears on the monitor]
- Berger: [next to the bridge door] That's not possible!
- The Doctor: Oh, he's very good, and almost right.
- [the Cybermen are softening a bridge door with a thermal lance]
- Cyber Leader: The shield is now soft enough. Break through!
- [the Doctor taps into the antimatter storage system and uses it to stabilize the door just as a Cyberman breaks through, with the result that the Cyberman is fused into the door]
- Cyber Lieutenant: Which one is the Doctor?
- Cyber Leader: The tall one with fair hair. Even under the threat of death he has the arrogance of a Time Lord.
- The Doctor: Those shields won't hold them there for long.
- Briggs: They'll last until we're back to Earth.
- The Doctor: And then?
- Briggs: There's only a few of them: our security men will cope with them.
- The Doctor: They're an invasion force, Earth is where they want to go. There are considerably more than a few on board.
- Adric: [looking at papers] How many of these silos are you carrying?
- Briggs: Oh, fifteen thousand or...
- [she stops, dawning that her entire cargo, each and every silo, in fact contains a Cyberman]
- Briggs: [softly] No. It's not possible!