James Doohan (Scotty) and Keith Andes (Akuta) previously appeared in The Outer Limits episode "Expanding Human". They played Police Lt. Branch and Dr. Peter Wayne respectively. Coincidentally, they both died at the age of 85 years and four months in 2005.

Walter Koenig stops wearing his wig in this episode.

Chekov: It makes me homesick. Just like Russia.
McCoy: More like the Garden of Eden, Ensign.
Chekov: Of course, Doctor. The Garden of Eden was just outside Moscow. A very nice place. It must have made Adam and Eve very sad to leave.

Scotty: I hear it's nice down there.
Kirk: Yeah. It's nice. If we're a little more careful, we shouldn't run into any more trouble.
Scotty: I could do with a nice walk in a garden with green leaves and grass.
Kirk: We'll do the walking, Scotty.

Landon: All this beauty, and now Mr. Hendorff dead,
somebody watching us. It's frightening.
Chekov: If you insist on worrying, worry about me. I've been wanting to get you in a place like this for a long time.
Kirk: Mr. Chekov, Lieutenant Landon. I know you find each other fascinating, but we're not here to conduct a field experiment in human biology.

Spock: Interesting. Extremely low specific gravity, some uraninite, hornblende, quartz. Fragile, good cleavage. An analysis should prove interesting.
Kirk: Would you mind being careful where you throw your rocks?
Spock: Obviously highly unstable, Captain. This could be a find of some importance. In large quantities, it could be a considerable source of power.
Kirk: Garden of Eden... with land mines.

Spock: Doctor McCoy's potion is acting like all his potions -- turning my stomach. Other than that, I am quite well.
McCoy: If your blood were red instead of green, you wouldn't have an upset stomach.
Kirk: What were you trying to do?
Spock: I surmised you were unaware of that plant, so I...
Kirk: Stepped in front and took the thorns yourself.
Spock: I assure you, Captain, I had no intention of doing that.
It was merely my own clumsiness that prevented me from moving out of the way.
Kirk: Next time, yell. I can step out of the way as quickly as the next man.
Spock: I shall do so.
Kirk: Trying to get yourself killed, you know how much Starfleet has invested in you?
Spock: 122,22 --
Kirk: Never mind. But... thanks.

Kirk: Spock... you and Chekov create a diversion and make it loud.
Spock: Mr. Chekov, your tricorder readings are totally inefficient!
Chekov: Mind your own business, sir! For your information, I have a very high efficiency rating!
Spock: Ensign, you will not address me in that tone of voice!
Chekov: What do you want, violins?

Kirk: Scotty... you're my chief engineer. You know everything about that ship there is to know. If you can't get those warp engines working... you're fired.

Akuta: These are the people of Vaal.
Kirk: Where are the others?
Akuta: There are no others.
Kirk: The, uh, children.
Akuta: Children? Ha ha. You use unknown words to me.
Kirk: Little ones like yourselves. They grow.
Akuta: Ahh! Replacements. None are necessary. They are forbidden by Vaal.
Landon: But when a man and woman fall in love ...
Akuta: "Love." Ha ha ha ha. Strange words--children, love. What is love?
Landon: Love is... when two people are ...
Akuta: Ahh... yes. The holding. The touching. Vaal has forbidden this.
McCoy: Well, there goes paradise.

(as Sayana gives them leis)
Kirk: It, uh, does something for you.
Spock: Yes, indeed it does, Captain. It makes me uncomfortable.
Sayana: I am Sayana. You have a name?
Spock: Yes. Spock. I am Spock.
Sayana: Ha ha ha. Spock?
(the natives laugh)
Spock: I fail to see what they find so amusing.

McCoy: What's going on, Jim?
Kirk: Mess call.
Spock: In my view, a splendid example of reciprocity.
McCoy: It would take a computerized Vulcan mind, such as yours, to make that kind of a statement.
Spock: Doctor, you insist on applying human standards to nonhuman cultures. Humans are only a tiny minority in this galaxy.

Landon: But these people, I mean, if they don't know anything about... what I mean is, they don't seem to have any natural... I mean, how is it done?
Kirk: Mr. Spock, you're the science officer, why don't you explain it to the young lady?
Spock: Well, I believe it's safe to assume that they would receive the necessary instructions.
McCoy: From a machine? That I'd like to see.

Landon: But these people, I mean, if they don't know anything about... what I mean is, they don't seem to have any natural... I mean, how is it done?
Kirk: Mr. Spock, you're the science officer, why don't you explain it to the young lady?
Spock: Well, I believe it's safe to assume that they would receive the necessary instructions.
McCoy: From a machine? That I'd like to see.

Spock: The good doctor was concerned that the Vaalians achieve true human stature. I submit there is no cause for worry. They've taken the first step. They've learned to kill.

Scotty: Captain, we pulled away a little, we gained... maybe an hour... but we blew almost every system in the ship doing it. There's nothing left to try again. I guess you'll have to fire me, sir.
Kirk: You're fired.

Akuta: Vaal... cared for us.
Kirk: You'll learn to care for yourselves with our help. And there's no trick to putting fruit on trees. You might enjoy it. You'll learn to build for yourselves, think, work for yourselves, and what you create is yours. That's what we call freedom. You'll like it, a lot. And you'll learn something about men and women, the way they're supposed to be--caring for each other, being happy with each other, being good to each other. That's what we call... love. You'll like that, too, a lot, you and your children.
Sayana: What are "children"?
Kirk: The ... little ones. They look like you. Just go on the way you're going. You'll find out.

Spock: Captain, you are aware of the biblical story of Genesis.
Kirk: Yes, how Adam and Eve tasted the apple and were driven out of paradise.
Spock: Precisely, Captain, and in a manner of speaking, we have given the people of Vaal the apple, the knowledge of good and evil if you will, as a result of which they, too, have been driven out of paradise.
Kirk: Doctor, do I understand him correctly? Are you casting me in the role of Satan?
Spock: Not at all, Captain.
Kirk: Is there anyone on this ship... who even remotely... looks like Satan?
Spock: I am not aware of anyone who fits that description, Captain.
Kirk: I didn't think you would.

The same type of lightning bolt that disintegrates Kaplan earlier merely scorches Spock on the back, leaving him with second degree burns.

The remastered version improved Vaal's weather attack by adding more realistic cloud shots - but this introduced a new goof. The sky was red at all times except during uplooks at the clouds. Those scenes featured a blue sky (probably because they were real clouds, and there wasn't time or money to alter the blue sky).

What Changed in the Remastered Version
General improvements cited on the main series page. The orbital shots of Gamma Trianguli VI get a surface upgrade and make it clearer that it is both a jungle-like planet, and as described in the episode the same temperature even at the poles. The Enterprise firing on Vaal is cleaned up with the newer phaser effect.