"Plato's Stepchildren" or "The Children Shall Lead" or "Let That Be Your Last Battlefield."
"A single line" ironing out a logical of some kind early in "The Children Shall Lead" would have done not a thing to save the story or even improve it very much - it was just shitty. Solving a minor plot flaw has very little to do with the quality of a story.
You're confusing story with storyTELLING. It's a horribly made episode, full of bad direction, bad acting, and bad choices for music and other peripherals, for which I curse the name of Fred Freiberger every chance I get. But the one line I mentioned(which would have added about two seconds of screen time) would have taken a non-sensical story and put at least a modicum of sense to it.
The Final Draft script dated June 21, 1968 sheds a little bit of light on this issue.
In Scene 215 after Mister Spock plays back the tape of the children's chant from earlier, Kirk moves from his position where he was standing near Spock's station and goes over in front of the turbo lift where Melvin Belli is slowly beginning to appear:
KIRK
The time has come to gather and
see the world as it is.
The shimmering figure of Gorgan begins to appear
before the boys who do not form a circle, only watch,
uncertain, confused.
KIRK
(continuing)
Come -- join us. You must
have a name.
TOMMY
(defiantly)
He is Gorgan. He is our friend --
and he is powerful.
Now Gorgan reaches full flower.
GORGAN
(confused)
Who has summoned me?
KIRK
I did, Gorgan. My beast is gone.
It lost its power in the light of
reality. I command again. And I
ordered you to appear.
It's hard to tell if the dialog was shot but not used or if it was simply never shot at all. My hunch, from looking at how the scene is edited, is that the little bit of dialog was indeed shot but not ultimately used.
It's a little plot hole, I guess, and it's hard to say why the two seconds of dialog wasn't used. I guess it slowed down the exquisite storytelling that was going on and I guess the writer and/or director and/or editor just figured that the audience would simply conclude that one of the kids told Kirk the name of this alien being offscreen at some point.
Like Dennis said: this line doesn't really salvage the episode. But it's interesting that it's not a plot hole that someone
forgot to fill; rather, it's a plot hole someone
intentionally chose to create for some unknown reason.