- The Doctor: Whenever you go into a new situation, you must always believe the best until you find out exactly what the situation's all about, THEN believe the worst.
- Romana: Ah, but what happens if it turns out NOT to be the worst after all?
- The Doctor: Don't be ridiculous. It always is.
- The Doctor: Where's your joy in life? Where's your optimism?
- Romana: It opted out.
- K9: Optimism: belief that everything will work out well. Irrational, bordering on insane.
- The Marshal: What is the purpose of your visit?
- The Doctor: Tourism.
- The Marshal: In the middle of a nuclear war?