In the throne room, the original emperor is being overpowered by the controlled clone. 001 then hears a stampede approaching.
“Someone’s coming.”, he says.
“What?”, the rest say.
They turn to the sound and watch the door. The doors suddenly thrust open to reveal the minions, humans and other creatures with armor and weapons.
“What?! How did they get past my robots?!”, Weaselegraft exclaims.
A monster growls to them. They don’t understand what it just said.
“What did it say?”, Kablooey asks.
“It said, you better surrender Keretomatus and leave this land.”, Martha says.
“What? How do you know my name?”, the emperor asks.
“Your minions helped us escape.”, Sarge says.
“We are not gonna give in to common and uncommon animals.”, Pablum says.
“Very well, we’ll do this the hard way.”, Skits says.
Before they can free the emperor, more robots approach them.
“What the…?!”, Spike shouts.
The goons laugh.
“You didn’t think those were the only robots we had, did you?”, Pablum says.
“No we came prepared.”, Weaselegraft says.
“Wow. They really have been taking notes.”, Twilight says.
“Attack!”, Neighsay says.
They charge as the creatures battle them out. The goons watch as the robots keep tackling the heroes.
“What are the odds. Two battles taking place in the same location.”, Kablooey says.
They turn and see the monsters still battling. The group begin to tire out.
“This is ridiculous.”, Rainbow says.
“Those guys must have programmed these robots to be relentless.”, Helen says.
“Relentless?”, Skits asks.
“’Relentless’ means oppressively constant or incessant. In other words tireless.”
“So how can we beat them if they’re relentless?”, Martha asks.
“Hang on. How did we beat those other robots?”, Pinkie asks.
“We sang a song.”, Garble says. “What about it?”
“Maybe we can use a song to defeat these robots as well.”
“Are you serious?!”, Ember says.
“Sorry to say this, Pinkie, well not sorry actually, but you can just forget it. I don’t sing.”, Garble says.
“Neither do I.”, Gilda says
“Would you rather be creamed by these robotic beings?”, Twilight asks. “Now what song can we use?”
“Yaks have one.”, Rutherford says.
“Rutherford, you have a song?”, Thorax asks.
“Of course. Ponies, changelings and hippogriffs not only creatures who can sing.”
They all think as the goons watch.
“What are they doing? Why are they just talking?”, Weselegraft asks.
“I’m not sure.”, Neighsay says. “I’ll take off the shielding spell.”
They then see the creatures standing defenseless.
“Are they just gonna stand there and do nothing?”
Suddenly, the yaks start harmonizing. They then start performing and sing. The robots get annoyed and try to attack them. The yaks then stomp to the rhythm on top of the robots, crushing them. The other creatures join in on the stomping. The goons send more robots and they all get destroyed by the singing group. The song ends and all the robots have been destroyed. They then turn to the goons.
“Never send robots to do a monsters job.”, Pablum says.
“Keretomatus, cease your attacking, go after the intruders instead.”, Neighsay says.
The monster then goes after the creatures. The creatures the battle against the monster as the crooks watch.
“Look at them”, Neighsay says. “Those fools have no idea what they’re in for.”
“That monster has power far beyond their comprehension.”, Gimmie says.
“Comprehension?”, Bumblecrum says.
“’Comprehension’ means the action or capability of understanding something.”, Stubble says.
“Well those creatures are gonna get creamed right now.”, Kablooey says.
“Nonsense, Kablooey.”, Weaselegraft says. “The monster is only weakening them. The real trap is almost ready.”
“Oh, yeah. I forgot about that.”
The monster continues fighting the creatures. They soon get tired.
“Guys. I think we’re tiring him out.”, T.D. says.
Suddenly, a trap door opens, and they fall in. The winged creatures fly over the trap door.
“What was that?”, Ralphie asks.
A vacuum comes out and sucks the winged creatures inside. The creatures then come out inside a dome.
“What? Are we inside a dome?”, Martha asks.
“You sure are.”, Pablum says. “That was all just a ruse to activate our real trap.”
“Real trap?”, Truman says.
“Don’t worry.”, Rutherford says. “I’ll break dome.”
He charges but hits his head on the dome. He then rubs his head and sees it’s still intact.
“What? Not even a crack?”, Spike says. “Maybe, I can do this.”
He takes a deep breath and breathes fire on it. He then sees that the dome still hasn’t been penetrated.
“It hasn’t melted either.”
“I’ve put a special spell on it, so nothing that causes damage can destroy it. It has to be something that no other specimen could think of.”, Neighsay says.
“Aw, man. What could we possibly use that doesn’t create damage?”, Sunburst asks.
“Oh, man. There has to be something that we can use.”, Gallus says.
While they’re all consulting each other, the crooks are watching them ponder.
“Well, we better activate the machine.”, Stubble says.
They head to the machine, before they get stopped by a voice.
“I got it.”
They turn to the voice and sees it was Pinkie who has her hoof up.
“Singing.”, she says.
“Singing?”, the group asks.
“It’s the one thing that doesn’t cause any damage.”
“Pinkie, do you really think singing will get us out of this dome?”, Rainbow asks. “I mean we’ve already sang two numbers already.”
“We’ve gotta try.”
“It’s true, Rainbow.”, Helen says. “Singing has vibrations strong enough to break glass.”
“Well it’s a stretch. But I guess we’ve got no other option.”, Twilight says.
The crooks then laugh at the idea.
“You honestly think singing songs will be enough to break that dome.?”, Weaselegraft asks. “I guess you really are that desperate.”
Twilight and Helen start their turn with their own song with birds and some shadows. Their song creates music notes that shoot vibrations to the dome. The dome doesn’t break.
“Oh, it didn’t work.”, Helen says.
“We better try another song.”, Twilight says.
“We’ll go next.”, Smolder says.
Smolder, Yona, Ocellus and Silver Stream perform their own song with the kids. They pet and cuddle them as their note send vibrations to the dome. The second song also has no effect.
“Just give up. None of those sissy songs will break that dome.”, Kablooey says.
Skits, Martha’s brothers, Gallus and Sandbar go up next.
“Our turn.”, Skits says.
They perform their song and do a dance performance along with it. Their notes give out their own vibrations. The song doesn’t break it either.
“Does anyone else have a song to perform?”, Persnickety asks.
Pharynx, Terramar, Garble and the cats go up next.
“We do.”, Pharynx says.
“Pharynx, you can sing?”, Thorax asks.
“Yes. But I don’t always sing willingly to anyone. I only do it when the time is right.”
They perform their song with some imps floating with the notes as they give off vibrations. The dome takes them in and nothing. The crooks then start laughing.
“Have you all run out of songs yet?”, Pablum asks.
“It’s not working.”, Gabby says.
“None of the songs are doing anything.”, Applejack says.
“Come on, everyone, don’t give up.”, Martha says. “There’s gotta be a song that’s bold enough to destroy this dome.”
“Who’s got a song they can give out?”, Skipper asks.
“I can’t think of any other song.”, Mrs. Klusky says.
“Guys, we can’t give up. There’s gotta be something we can do.”, Helen’s grandpa says.
“Well what can we do?”, Helen’s abuelo asks.
“Oh, well. We better start that machine already.”, Neighsay says.
The groups then start panicking.
“Come on, everyone. Think.”, Skits says.
They all start yelling and screaming ideas.
While this is happening, the emperor still lies unconscious.
He then opens his eyes and sees he’s in an unknown realm.
“Wh…Where am I?”, he asks. “Am I dead?”
“No. You’re not dead.”, a familiar voice says.
He turns to the voice and sees his sons, Martarmus, Horlagamous and Scorjosemal in front of him.
“My sons. Is it really you?”
“Yes, Father. It is us.”, Martarmus says. "Your beloved sons."
“Where are we?”
“This is limbo. We’ve sensed your aura was weakened, and we’ve used our astro projection to find you.”, Horlagamous says.
“Well what can I do? All of those creatures are about to become enslaved, and I couldn’t protect them.”
“Don’t lose hope, Father.”, Scorjosemal says. “Remember what Star Swirl says. You need to find your inner monster and release it. Only then will you save the creatures from both worlds.”
"You can't give up. You are Emperor Keretomatus. The most powerful ruler in all of Equestria. Next to Celestia and Luna, of course.", Martarmus says.
"Just look at what you did to save those creatures from being captured and controlled.", Horlagamous says. "You could never disappoint us. And that's why you need to awaken and reclaim your kingdom."
His sons then start to fade.
“My sons, where are you going?”
“Don’t lose hope.”, they all say to him before they vanish. "Fight for what's right."