- Yeoman Rand: That little girl...
- Mr. Spock: ...is at least three hundred years older than you are, Yeoman.
- Yeoman Rand: Miri... she really loved you, you know?
- Capt. Kirk: Yes.
- [pause]
- Capt. Kirk: I never get involved with older women, Yeoman.
- Dr. McCoy: Now this is marvelous. The most horrible conglomeration of antique architecture I've ever seen.
- Capt. Kirk: Listen to me! You've got our communicators, the boxes we talk into. We need them to talk to the ship.
- Redheaded Boy: Blah, blah, blah!
- the other children: Blah, blah, blah!
- Capt. Kirk: No "blah, blah, blah!"
- Dr. McCoy: It's dead. It's incredible.
- Capt. Kirk: What is?
- Dr. McCoy: It's metabolic rate. It's impossibly high, as if it burning itself up. Almost as if it aged a century in just the past few minutes.
- Capt. Kirk: Bones.
- Dr. McCoy: Hmm?
- Capt. Kirk: Why do you think the symptoms haven't appeared on Mr. Spock?
- Dr. McCoy: I don't know. Probably the little bugs or whatever they are have no appetite for green blood.
- Mr. Spock: Hmm. Being a red-blooded human obviously has its disadvantages.
- Capt. Kirk: This is the vaccine?
- Dr. McCoy: That's what the computers will tell us.
- Mr. Spock: Without them, it could be a beaker full of death.
- Capt. Kirk: Just children. 300 years old and more. I've already contacted Space Central. They'll send teachers, advisors...
- Dr. McCoy: And truant officers, I presume.
- Capt. Kirk: They'll be all right.
- Capt. Kirk: What'd you find?
- Dr. McCoy: The disease, Captain! The one they created three hundred years ago.
- Yeoman Rand: There's a chance!
- Dr. McCoy: There's a chance. At least it's a race now, and we just wasted a minute.
- Capt. Kirk: You two will have to recreate their thinking. If you can isolate that virus, you'll be able to develop a vaccine.
- Dr. McCoy: [Spock and McCoy trade incredulous looks] Is that all, Captain? We have five days, you know.
- Mr. Spock: According to their Life Prolongation Plan - what they THOUGHT they were accomplishing - a person would only age one month for every one hundred years of real time.
- Yeoman Rand: One hundred years? And only one month?
- Mr. Spock: Exactly, Yeoman. Evidently, through some miscalculation, this virus annihilated the entire adult population in a very short period, leaving only the children.
- Yeoman Rand: But that means these children...
- Mr. Spock: ...could very well be immensely old.
- Capt. Kirk: [temperamental after several days of no results and just getting more sick and no way to contact the ship] Haven't you found anything yet?
- Dr. McCoy: [irritated] Would you like to take a crack at it?
- [storms off]
- Capt. Kirk: Don't you know why you don't like to play games anymore, why you don't see your friends the way you used to? It's because you're becoming a young woman; and, the moment you become a young woman you get the disease - ALL of you.
- Miri: It's not true. It just happens sometimes.
- Capt. Kirk: ALL THE TIME, Miri! It's happening to you RIGHT NOW!
- [Kirk exposes her diseased arm]
- Capt. Kirk: Look at it! Look at it, Miri! It's in YOU!
- Miri: No. No! NOOOOO! NOOooo!
- Jahn: Now, what does a teacher say, heh?
- Redheaded Boy: [thinking] Yeah... Study-study-study or bomp-bomp, bad kid!
- [first lines]
- Capt. Kirk: Earth style distress signal. SOS.
- Farrell: I've answered it on all frequencies, sir. They don't reply.
- Yeoman Rand: [upset] Back on the ship, I used to try to get you to look at my legs. Captain, look at my legs.
- [as he looks, she involuntarily covers the blue scabs growing on them]