"Do Not Disturb"
The Lightning League helped a race of felinoids (cat-people) defeat a swarm of Monster Mind troopers.
They then taught them how to fight for themselves by staging seminars in the felinoids' city. Jayce reviewed battle tactics, Flora showed them how to communicate with plants, and Gillian demonstrated the use of certain magical stones. Herc entertained some felinoids by telling war stories, but he was thrown out after making one too many cat jokes. Oon wandered from class to class, gradually becoming upset because no one needed his help; he felt lonely and useless.
Suddenly, one of Gillian's magical stones detected an incredible power nearby. Gillian, Jayce, and Oon traced the power to a nearby cavern hidden deep beneath a mountain. They found a huge set of metal doors sealed with a golden snake twisted into the shape of an "infinity" sign. Gillian translated the ancient writing on the doors, which warned that a powerful, magical demon named the Night Walker was imprisoned behind them. He was sealed away because his only purpose was to destroy. Gillian warned Jayce not to remove the seal, and the two of them left.
Oon, however, thinking that the seal was pretty, removed it to get a better look. The doors cracked open slightly, revealing two glowing red eyes in the darkness beyond. The Night Walker asked Oon what he wished in return for freeing him. The squire replied that he wanted the Monster Minds destroyed. The demon agreed to this request but insisted that the seal be left in the cavern. Oon happily dropped it and ran off to join his friends. The Night Walker knocked down the metal doors, burying the seal beneath, and left the cavern to destroy all in his path.
Back at the felinoid city, the League prepared for another Monster Mind attack. But the preparations were unnecessary; as the enemy troopers advanced, they were disintegrated by mysterious beams of energy. The Night Walker was attacking the Monster Minds! Oon, proud of himself for discovering this great ally, revealed that he was the one who freed the demon. Gillian warned that after the Night Walker was done with the Monster Minds, he would turn on them.
Gillian and Flora went to fetch the seal while the others distracted the Night Walker. Flora convinced the plants in the cavern to grow tall and strong, thus lifting the fallen doors so that Gillian could reach the seal.
Meanwhile, Oon tried to control the demon, ending up getting captured for his trouble. Jayce gave the Root to Herc, then challenged the Night Walker to a one-on-one battle. The demon deposited Oon on top of a high mountain and turned on Jayce. But Jayce was too quick for him! He grabbed hold of the Night Walker's black cape and started climbing, noticing that on back of the demon's neck was an impression in which the seal would fit. Gillian arrived from the cavern and gave the seal to Herc, who in turn tossed it to Jayce. The demon knocked the seal away, but Oon neatly caught it.
Oon used his Magic Lance to vault himself over to Jayce, who then took the seal and placed it within the impression, draining away all of the Night Walker's energy. The Lightning League placed the demon back in the cavern and resealed the doors. Jayce then invited Oon to teach the felinoids about the lesson he had learned. Everyone returned to the cat-people's city for a resumption of the seminars.
Jayce: "Lightning Strikes!"
Terror Tank: "He attacks our troopers by himself! The boy must be mad!"
Saw Boss: "Or very clever..."
(After a squadron of Terror Troopers fell into a sudden chasm created by Drill Sergeant)
Herc: "Kinda give a whole new meaning to the word 'stupid,' don't they?"
Herc: "And that's how we defeated a whole planet full of the Monster Minds. I did most of the work, of course. But, uh, the kid helped."
Gillian: "If I read these signs properly, beyond those doors is a Night Walker. A creature of metal and magic, alive and not alive. Dedicated to only one thing: destruction. Legend says there were three. They were imprisoned in such places because only the strongest will could control them."
Oon: "W-W-What, ah ah who are you? Wh-Wh-What do you want?"
Night Walker: "Why, to serve you, of course! I must, because you freed me. You may ask me to do anything you want."
Oon: "You m-m-mean, you w-w-won't hurt me?"
Night Walker: "Of course not! You are my Master now. You want to help your Master to defeat his enemies, to prove your value to him."
Oon: "Well, yes I do! Can you destroy all the Monster Minds?"
Night Walker: "Certainly! And then I shall return here, to my sleep of ages..."
Night Walker: "Yes, my little fool, I shall destroy your enemies for you, because I must. And then I shall destroy you, and your friends, and every living thing in the universe, starting with your Master!"
Oon: "I can't wait until you see my surprise, Master. It will make you so happy!"
Jayce: "I'm sure it will, Oon. You never let me down yet."
Oon: "But I'm not much of a help, either."
Flora: "Of course you are, Oon! You help keep us together, and I think you're braver than you think you are."
Gillian: "She's right, you know, Oon."
Herc: "And you're always good for a laugh!"
Oon: "Gee, I didn't... I mean, I..."
Herc: "Waaait a minute! Did you say we're going to hold off THAT -- by ourselves?!"
Jayce: "Yes."
Herc: "Yeah... that's what I thought you said."
Saw Boss: "Gun Grinner, give me a computer analysis."
Gun Grinner: "Records indicate creature is called a 'Night Walker.' Its purpose: destruction, of everything!"
Saw Boss: "And our odds for success against it?"
Gun Grinner: "Zero!"
Saw Boss: "Hmmm, destruction of everything..."
Jayce: "It's coming our way!"
Oon: "How're we going to stop it?"
Jayce: "Any way we can!"
Herc: "Kid, I just want you to know something: I'm not enjoying this!"
Oon: "I just wanted to help... to be useful."
Jayce: "But sometimes an easy solution is more dangerous than the problem! In fact, I was hoping you could tell one of our classes about it before we leave."
Oon: "Me? Teach?
Jayce: "We all have something to teach, Oon, and I think you've learned enough to teach ten classes today! Now let's go."
