- Dr. Jeremiah Morley: I believe that humanity can escape annihilation, can find a temporary haven, a promise of hope that, come what may, life can be sustained deep within the Earth itself. Far below the Earth we shall seek a natural, a geologic shelter. We have a team ready for the effort. All we lack are funds.
- Andy Ostergaard: [Reflecting on the expedition's status deep beneath the Earth] You know once when I was working on the Holland Tunnel, I got cut off from my crew for ten hours. I felt this way then.
- Dr. James Paxton: Nature doesn't influence Man! Man influences Nature! One man, one strong man can change Nature!
- Wright Thompson: Oh, you're wrong, Dr. Paxton. It isn't one man, it's many men working together.
- [Looking at Dr. Joan Lindsey]
- Wright Thompson: Right, teacher?
- Dr. James Paxton: Men together are no more than sheep! One man standing alone leads the way, and the sheep follow!
- Wright Thompson: What kind of place is this? Flowers that crumble to dust in your hand, stones that look like pearls, fish without eyes! Nature's sure a practical joker!
- Dr. Jeremiah Morley: I suppose you could've done better?
- Wright Thompson: In 10 million years I couldn'ta done worse!
- Dr. Jeremiah Morley: Go back to what? To a world bent on self destruction? We can live the rest of our lives here in peace.
- Dr. Joan Lindsey: Morley, you're wrong! This isn't peace! This is a resting place for the living dead! I don't believe it's the end of the world! I don't believe it's the end of mankind!
- Dr. Jeremiah Morley: You're young! You don't know! I've lived through the terrors of two great wars! I've had enough!
- Wright Thompson: You don't like my kind of guy, do you?
- Dr. Joan Lindsey: Not very much, but I'll make an exception in your case-you, I don't like a lot.
- Wright Thompson: [referring to the scientists] Don't they ever talk?
- Andy Ostergaard: Not unless they got something to say. That's the way it is with smart people,
- Wright Thompson: Maybe they're not so smart. Maybe they don't know what they're doin' down here.
- Andy Ostergaard: Listen, buster. Each one of them has taught at more colleges than you flunked out of.
- Wright Thompson: So what are you doing down here among all those brains?
- Andy Ostergaard: I manage to make myself useful. It might be well if you did the same thing.