- Chekov: [darkly] Give some more blood, Chekov. The needle won't hurt, Chekov. Take off your shirt, Chekov. Roll over, Chekov. Breathe deeply, Chekov. Blood sample, Chekov. Marrow sample, Chekov. Skin sample, Chekov. If-if I live long enough, I'm going to run out of samples.
- Sulu: You'll live.
- Chekov: Oh, yes, I'll live, but I won't enjoy it.
- [Lt. Galway sees her aged image in a mirror in the Sick Bay doorway]
- Arlene Galway: What a stupid place to hang a mirror!
- Commodore Stocker: I would like you to take over command of the Enterprise.
- Spock: On what grounds, Commodore?
- Commodore Stocker: On the grounds that the captain, because of his affliction, is not able to perform his duties.
- Spock: Need I remind you, sir, that I, too, have contracted the same affliction?
- Commodore Stocker: Yes, but you're a Vulcan. You've a much greater lifespan. You show the effects to a much smaller degree.
- Spock: I'm half-human, sir. My physical reflexes are down. My mental capacity is reduced. I tire easily. No, sir. I am not fit for command.
- Commodore Stocker: Well, if you are not, with your Vulcan physique, then obviously Captain Kirk can not be.
- Sulu: Entering Romulan Neutral Zone, sir. All sensors on maximum.
- Commodore Stocker: Thank you, Mister Sulu. Lieutenant Uhura, let me know if we contact any Romulan.
- Uhura: [the ship is hit by incoming enemy fire] I think we just made contact, sir.
- Spock: Doctor, ship's temperature is increasingly uncomfortable for me. I've adjusted the environment in my quarters to 125 degrees, which is at least tolerable. However, I...
- McCoy: Well, I see I'm not gonna be making any house calls on YOU!
- Spock: I wondered if perhaps there was something which could lower my sensitivity to cold.
- McCoy: I'm not a magician, Spock, just an old country doctor.
- Spock: Yes. As I always suspected.
- Captain James T. Kirk: [to Spock] You traitorous... disloyal... you stab me in the back the first chance you get. Spock... get out. I never want to have to look at you again.
- McCoy: Anytime you're ready, Mr. Spock.
- Spock: I am quite ready now, Doctor.
- McCoy: Because of your Vulcan physique, I've prepared an extremely potent shot for you. However, I thought you'd might like to know that I've removed all the breakables from sickbay.
- Spock: That is very considerate of you, Doctor.
- Captain James T. Kirk: Maintain standard orbit, Mr. Sulu.
- Sulu: You already gave that order, sir.
- Captain James T. Kirk: Oh? Well... FOLLOW it.
- McCoy: [checking out the Captain's twinge] Jim, I think we'd better run a complete physical on you.
- Captain James T. Kirk: Why? Just muscular strain, hmm?
- McCoy: No, Jim. It's advanced arthritis. It's spreading.
- Arlene Galway: [from the blooper reel] Doctor, may I speak to you for a moment, please?
- McCoy: Of course.
- Arlene Galway: Well, I know this is going to sound foolish, but
- [Beverly Washburn breaks character]
- Arlene Galway: I feel like hell! I've forgotten my next line!
- Spock: Doctor, we made the necessary computations and produced this serum. It is crude, and dangerous, but we had no time for refinements.
- McCoy: All right! Let's... let's go!
- Spock: It could cure - or kill, Doctor.
- McCoy: Don't give me any Vulcan details, Spock. Just give me the shot!
- Captain James T. Kirk: No... *I'll* take the first shot.
- Captain James T. Kirk: [after his competency hearing has been concluded and he's back in his quarters] I made a fool of myself in there. I shouldn't have let them confuse me... rattle me.
- Janet Wallace: [trying to be sympathetic] Everybody understood.
- Captain James T. Kirk: But I am not *old*, Jan. I'm NOT.
- [begins wheezing]
- Captain James T. Kirk: A few muscular aches doesn't make a man old. And you don't run a starship with your arms, you run it with your head! And my brain's as sharp as it ever was. A simple case of radiation poisoning and they relieve me of my command?
- Captain James T. Kirk: [stops to look at himself in a mirror] I admit I'm getting a little gray, but radiation will do that to ya'.
- McCoy: [to Spock] Oh, you're perfectly healthy.
- Spock: I must differ with you, Doctor. I'm having difficulty concentrating, which is most disturbing, my eye sight appears to be failing, and the normal temperature of the ship seems to me to be increasingly colder.
- McCoy: I did not say you weren't affected, Mr. Spock. You are perfectly healthy. That is, for any normal Vulcan on the high side of 100.
- Spock: Based on what Dr. McCoy gave me, I estimate that physically we each have less than a week to live. Also, since our mental faculties are aging faster than our bodies, we'll be little better than mental vegetables in a considerably lesser time.
- Captain James T. Kirk: Oh, Mr. Sulu, increase orbit to 20,000 mile perigee.
- Sulu: You mean, ANOTHER 20,000, Captain?
- Captain James T. Kirk: I fail to understand why each one of my commands is being questioned. Now do as you're told, Mr. Sulu.
- Spock: Mr. Sulu, what is our present position?
- Sulu: Orbiting at 20,000, sir.
- Nurse Christine Chapel: [in a scene often deleted for syndication] Come on, Ensign. It won't hurt. Much.
- Chekov: Promises.