Ever since Krel had the idea of making a wormhole to travel to Akiridion, he's been working on it in the ship ever since but the process is not that simple. Right now, he's continuing after upgrading Ajas serrator.

Krel: I upgraded your serrator like you asked. It may be a little too strong for you.

Aja excited try the upgrade.

Aja: Too strong for me? Ha! Now I can actually manifest an ionic boomerang. I can't wait for the boom.

Krel: Careful. It's going to be hard to control.

Aja: I got this.

Right when she fired, she didn't withstands the recoil and the impact knock her back.

Aja: Kleb...

Krel: I told you, you need to be focused.

Aja: I know. You'll see.

Krel: Luug, drop the ball.

Luug drops it for Krel to pick it up.

Krel: Now, Luug, prepare to be amazed as your Mr. Happy Ball travels through a wormhole to another planet galaxies away.

Aja tries it again and ends up the same while Krel opens a small wormhole to give it another test.

Krel: Attempt 37 is a go!

He throws the ball into the wormhole.

Krel: (GASPS.) Seklos and Gaylen! I-It's working? (Laughs.) This time it's really-

The wormhole then spits out the ball that was shredded to pieces.

Krel: Ugh, busted.

Mother: [Good idea not testing the wormhole on yourself, my royal.]

Krel: I'm not a soolian, Mother. If only I could counteract the electromagnetic fields and prevent the spaghettification. (Pets Luug.) Who's a good boy? You are! Yes, yes, you are! Now, go get another ball.

Aja: (Laughs.) Spaghettification. Sorry, geezer, but that's my new favorite human word!

Aja tries the upgrade one last time and once again, ends up the same.

Krel: We need some sort of antigravity suction.

Aja: (Gasps.) You mean like the kind that could lift a car into the sky in the middle of Driver's Ed?

Krel: Aha! The Zeron's retrieval ray! I told you I wasn't a soolian, Mother!

Aja: That was my idea.

Soon they head out with Ajas hover board while Luug stays behind.

Aja: Be good while we're gone, Luug.

Krel: And keep away from that wormhole. Now, Luug, stay!

Just when they were about to head out, Varvatos Vex stops them.

Aja: Varvatos, what are you doing? We're going on a retrieval mission.

Vex: Varvatos Vex cannot allow you to leave.

Zadra: For once, Commander Vex and I are in agreement.

Aja: I liked it better when they were arguing.

Zadra: You've been summoned by the local educational board to partake in a different mission, one we believe might be crucial to maintaining your human identities.

Krel: Fine, but you have to pick something up for us.

Aja: What's our mission?

Time skip

Aja and Krel ends up at summer school where the school bell rings and Lawrence enters the classroom.

Lawrence: Welcome to summer school! All right, listen up, slackers. This is boot camp for your brain. Now- What? Aarg?

Aarg is sitting by the desk next to Toby and YN.

Lawrence: What are you doing here?

Toby: Uh he's looking to expand his educational horizons.

Aarg: (Eats a book.) Also got hungry.

Lawrence: (Excited.) Just imagine if we got you on the wrestling team. We'd finally make it to state!

YN: Um, he's a troll, coach. He can't be outside during daylight.

Lawrence: Oh right. I'm getting ahead of myself. First, we gotta do attendance. Wait, Tarron? You don't belong here.

Krel: Finally, we agree on something.

Lawrence: Slow your roll, DJ Kleb. Aja, it says you need to make up gym? But you're my star athlete. And why are you even here, YN?

YN: I got bored back home.

Aja: (Whispers.) This doesn't make any sense. There must be some mistake. (To Toby.) What are you in for?

Toby: I missed 45 days of school. Apparently Trollhunting's not good for your GPA.

YN: Especially after saving the world. Twice.

Toby: You okay, wingman?

Aarg: (Eats another book.) Mmm! Education tasty.

YN: Uh, guys, aren't those the same trucks we saw from before?

Aja and Krel look outside of the window to see the military arrive with protection suits and enter the school with colonel Kubritz and Sargent Costas.

Kubritz: Stick to the cover story and keep the neurometers charged, boys. These aliens already slipped through our fingers once.

Costas: Actually, ma'am, it happened twice.

Kubritz: It happened once. Okay.

Some of the soldiers are scanning the area as Lawrence speaks to the colonel.

Lawrence: How can I help you, sir uh, ma'am?

Kubritz: Colonel Kubritz, Scientific Military Division. There's been reports of a localized biohazard. We have to make sure no one is infected with this foreign pathogen lest we have a full-blown outbreak.

Mary: Outbreak? You don't think it's Jim Lake disease?

Darci: No, because that isn't real.

Mary: What? I donated to Eli's Walk for a Cure.

One of the soldier is scanning Lawrence.

Lawrence: Hey, watch it! Watch it! Hey! Is this really necessary? The school's healthy, Doc. I should know. I teach gym.

Colonel: That's our judgment to make.

Meanwhile the trollhunters and the royals are watching everything from the door window before hide in cover.

Toby: Why do I get the feeling these aren't doctors who hand out lollipops?

Krel: Because these so-called "doctors" are here for us. (Gasps.) Summer school it's a trap!

YN: And we fell right into it. Guys, if they find us, then they'll be asking questions for anything suspicious.

Toby: Especially Aarg.

Aarg: Mhm.

Krel: We'll have to avoid and sneak out way out.

Everybody agreed and they sneak through the hallway while some of the soldiers are questioning the students.

Costas: And have you noticed anyone acting unusual lately? Like maybe they don't belong here?

Mary: Uh, like him?

Costas: That's Teddy.

Teddy: How's it going?

Costas: He's cool. Anyone else?

Mary: (Scoffs.) Welcome to Arcadia, soldier. Being weird is, like, "our thing".

Just then they were gonna turn left, YN raise his fist to stop everyone before stomping his feet to the gound to seismic sense through the whole school.

YN: There's a lot of them throughout the school building.

Aja: This is bad.

Krel: These people imprison extraterrestrials.

Aja: They won't have a problem throwing you under a microscope either.

Aarg: Mmm, pass.

Krel: You guys get out of here.

YN: What about you guys?

Krel: We'll distract the guards' attention and meet back up with you at the mother ship.

Toby: Okay, are you guys sure about this?

YN: Yeah, I don't like this. They're here for you.-

Aja: Hey!

Aja gets the soldiers attention.

Aja: Evil mad scientist henchmen. Distraction! Distraction!

Krel: Your distraction is a little obvious.

Soldier: Get back to quarantine.

Aja: Let's see you quarantine this.

Aja and Krel then reveal themselves in their true form.

Soldier: It's them!

With that, the royals run of with the soldiers on their tale, giving the others an opportunity to escape.

Krel: Now it's really obvious.

Aja: It's working, isn't it? And you said summer school wouldn't be fun.

Soldier: Stop right there!

Aja: Cover me!

Aja uses her serrator to cut the fire extinguisher to cause a cloud of smoke to blind the soldiers. With that, theyanage to escape until the powers shut down.

Krel: Oh, no.

The electricity crackling through the hall as Tronos appears.

Tronos: (Roaring.) Running is useless.

Soon they were blocked by Kubritz at the other side of the hallway.

Kubritz: So is hiding.

Aja pulls out her serrator and ready to fire.

Krel: Focus, Aja.

Aja: What does it look like I'm-

Out of nowhere, colonel takes Aja down while Tronos take Krel down.

Kubritz: Perhaps you didn't notice my medals. You're not the only female with combat training here. I made a few upgrades since our last meeting. (Chuckles.) Take them to gym class. Looks like school's back in session.

Costas: Nice one, ma'am.

Meanwhile with the Trollhunters, they manage to escape thanks to YN making a path to the sewers. From there they walked while YN tries to call Aja a couple times until Aarg speaks.

Aarg: Mm, no answer?

YN: Not even close. I'm starting to get more worried for them.

Toby: but that doesn't mean anything. Aja and Krel's phone probably fell in the toilet. We've all been there.

YN: That doesn't even make anything better.

Toby: You never know if they did.

Aarg: Or?

Toby: Hey, Aja and Krel said they've got this. They're some of the strongest, most butt-kicking-est warriors I've ever seen.

YN: Toby, this isn't gumm-gumms we're dealing with. These ate military we're really dealing with. Area 51 kind of military.

Toby: Yeah but they got some cool stuff to fight.

Aarg: Even strongest warrior needs wingman.

YN: I don't like this. I'm going back.

Toby: We can't go back.

YN: I am, because I'm worried about Aja. And Krel of course. Look, this'll be easy if we split up.

Toby: (Sighs.) Right.

YN: Aarg, get to the mother ship, see if you can find Zadra and the big guy. Toby?

Toby: I'll call in the cavalry.

YN: Alright. (Cracks knuckles.) Time to save the princess.

Aarg: Ahem.

YN: And the prince for a bonus.

Toby: Good luck.

With that, they all split up.

YN POV

I got back to the school and open the hatch that I made a while ago for Trollhunter problem. I take a peek to see if the coast is clear. 

Lawrence: I can feel it eating me from the inside. I'm a shell of a man!

Costas: Now, what else can you tell me about Aja and Krel?

Lawrence: But wh- why are you asking about them? I'm the one that's dying, aren't I!?

Costas: Um right.

Lawrence: Hey, I thought you said this was a medical quarantine.

Since they're the only ones outside, I sneak my way to the locker room and lift it up to grab my backpack where I kept my armor until I heard a soldier.

Soldier: Hey, what are you doing here? Put that down!

On second thought, I got a better idea.

YN: Sorry, thought I saw a rat here.

I put the locker back down with my earthbending.

Soldier: Hey, Dow did you-

Without a second thought, I knock him out with a punch takes off his safety suit and use it to disguise myself before leaving him inside the locker. With that, I can sneak through the school without getting anyone suspicious of me. Soon I arrive to the gym where they made it into a lab and I saw Aja in a glass container.

Soldeir: The seals are set tight.

Soldier2: We're using that for the gene applications. Let's take these off.

I start blending in to see what I can do to help, an assault would be a best option, but too risky since they got advance weapons. All I can to is listen while planning to strike in a right moment.

3rd POV

Aja then wakes up to see that she's tied on the lab bed.

Aja: Where am I? Krel! Krel! Where are you?

She tries to free herself until she hears Tronos voice.

Tronos: He's with Colonel Kubritz.

Aja: You're cooperating with her? Is there no low you won't stoop to for your precious bounty?

Tronos: You think I care about crestons? I'm doing this to avenge Voltar.

Aja: Voltar was destroyed long ago.

Tronos: Thanks to your parents. They helped destroy my home world.

Aja: Liar! My parents are honorable.

Tronos then appears in front of Aja.

Tronos: Not as honorable as you think!

She then notice one of the soldiers arrive to leave Krel on the other bed who seems to be unconscious.

Aja: (Gasps.) Krel! What did you do to him?

Kubritz: The same thing I'm going to do to you.

She picks up Ajas serrator.

Kubritz: With your weaponry in my hands, I'll be able to wipe every last alien threat from existence.

She split the table in half with her weapon and laughs.

Kubritz: For good.

Aja: Akiridion technology is meant to ensure peace, not bloodshed.

Krel: (Coughing.) Aja?

Aja: It's okay, little brother.

Kubritz: Once I finish dissecting you, Mr.
Madu will get your remains and his bounty, and I'll get the technology that you leave behind.

She starts with Krel by using Ajas serrator.

Kubritz: If this serrator can slice so easily through metal, imagine what it can do to your bodies.

Krel: (Nervous chuckles.) No. No, no, no. No need to imagine. I am sure it would hurt really bad.

Kubritz: Only one way to find out.

Just then a soldier enters the lab.

Soldier: Colonel, there's been um a situation going on.

Kubritz: Ugh, what kind of problem?

Soldier: There's been reports of earthquake going on in school.

Kubritz: Earthquake? I didn't even felt anything shaking.

Soldier: You're about to!

The soldier punches the ground and causes the ground to shake.

The colonel lost her balance before YN side kick the colonel against the wall.

YN: Ain't nobody messes with my Akiridion girl. And before you say it, Krel. Yes, especially my friend.

Krel: Appreciate it.

Soon the doors open, revealing its Steve and Toby.

Toby: Looks like class is-

The doors shuts back and they open it again.

Toby: Class is dis-

It happened again and this time they hold the door.

Class is dismissed. It's dismissed!

Soldier3: Hey, you can't be in here!

Toby and Steve starts taking down the soldiers.

Soldier: Looks like the Calvary arrives.

Krel: Wait. Who are you?

Soldier: Oh, right. The suit.

He takes off the mask to reveal its YN which made Aja smile.

Aja: YN!

YN: (Smirk.) Stone knight is here to save you my sapphire princes.

Krel: Pfft! That's what he calls you?

Kubritz: In a moment, he won't call you anything again.

She uses Aja weapon and aims at YN but he was quickly snatches it away from her with his metal cables before he did a sweep kick, knocking her out for the moment.

YN: Nice try, but gender equality. Except for my girl.

YN frees Aja and Krel from the binding.

Aja: You came to rescue me.

YN: Always. I mean what kind of boyfriend would I be if I left his girl behind?

She kisses YNs cheek which made him blush happily.

Krel: Ugh! Please kill me or at least leave.

Toby: Guys! Royals! Someone!

Steve: More of them coming. We gotta go!

They manage to escape the gym and YN block the doors with his earthbending.

YN: That'll hold them.

Toby: The hazmat guys blocked all the exits.

YN: We gotta get to the locker room. There's a hidden path that we can use to escape.

Steve: We'll distract them while you guys make you way there.

Aja: We can't leave you guys here!

YN: She's right, we don't leave a friend behind.

Steve: Don't worry. We'll hold them off.

They nod and were about to leave until the lights starts flickering again. Revealing its Tronos at the end of the hall. He was about to blast electric until YN earthbend a wall to block him before they all run off.

YN: He cut us off our escape.

Aja: I have an idea. Follow me.

They got to the rooftop and Aka and Krel use her hoverboard to escape while YN stays behind to hold off Tronos. But Tronos arrives and snatches the hover board and throws it away.

Tronos: Going somewhere?

YN: Pebbles, this guy's everywhere!

Aja: Tronos, you're working with the wrong people. Colonel Kubritz is using you. Please help us.

Tronos: Help? When my planet was besieged by war, we begged House Tarron for help. When we needed help the most, they left Voltar to burn.

Krel: Our parents would never do that.

Aja: Mama and Papa didn't help Varvatos' family either.

Krel: Don't believe his lies, Aja.

Tronos: I would have ended the king and queen myself if I had the chance, but I'll settle for the two of you.

YN: Leave them alone!

YN goes for the punch, but Tronos disappear and reappear behind YN to electrify YN.

Aja: YN!

Aja pulls out her serrator and aims.

Krel: Focus, Aja.

Aja: Stay away from him!

She fires but misses it.

Tronos: You'll have to be a quicker shot than that.

He laughs until the royals notice the blast is coming back.

Krel: It works! It's coming back!

Before Tronos notice it, it hits him from behind and he fell from the rooftop.

Kaja: That? That's what it does!?

Krel: Klebtastic, right?

Aja quickly checks on YN.

Aja: Are you okay, YN.

YN: (Coughs smoke.) Shockingly fine. (Chuckles.)

Krel: Less talk. More shooting!

Tronos jumps back on the rooftop and Aja starts firing at him.

Krel: To the left! Right! Left! No, no, no! Right again! Right! Right! Aim! Aja, aim!

YN: I have an idea! Jump!

Aja grabs krel and they all jump before YN uses his cables to swing down and landed by the bushes.

Krel: (Groans.) I hate your ideas you two.

YN: As long as it worked.

Aja: (Sighs.) On the bright side, we survived the fall.

Tronos: When I'm done with you, you'll wish you hadn't!

Tronos blasted electricity at them and they evaded it as Krel shield them with his serrator. Aja and YN nods and he gave her a boots by giving her a lift to get higher for her to get an opening. But Tronos saw it coming and uses his tail to knock her back down before YN catches her before Tronos appear in front of them. YN was about to use his earthbending against him until Tronos was blasted by the military. 

Kubritz: Drop the serrators and put your hands in the air.

Kubritz: I said you'll get your cores when I'm done, not before. Throw him in the van.

They take Tronos away before the colonel faces the three.

Kubritz: Oh, don't cry. I'm sure you'll find our detention center quite comfortable. Especially your rockkid friend.

Aja and Krel quickly disguise themselves before the school arrives.

Lawrence: Hey! The only one who gets to send these kids to detention is me!

Steve: You tell her, Dad I mean, Coach. Uh, Coach-Dad. Uh D-Daddy-o?

Kubritz: Stand down, sir. You have no idea how dangerous this situation is.

Darci: (Scoffs.) Dangerous? These are our friends. What have they even done?

Lawrence: You lied to me once, and now you're lying to me twice. I'm not dying, so what's this medical quarantine really about?

Kubritz: These children aren't from around here. They may be carrying disease and need to be removed for the safety of this community.

Mary: Sorry, could you repeat that?

She hold out her phone and starts recording the military.

Mary: You know, the part about how the kids "who aren't from around here" are "dangerous" and "sick" and "need to be removed"? I'm sure that's gonna sound great in a viral video.

One by one, everyone classmates including coach Lawrence hold out their own phones and start recording which surprises the royals.

Aja: Whoa! Lively!

YN: That's the power of Arcadias society.

Costas: Colonel, we need to go.

Lawrence: Take a hike, okay? Before I call the school board.

Having no choice, they decided to leave the school.

Kubritz: Move out. This facility has been cleared. This isn't over.

They all leave for good and Aja hugs YN.

Aja: (Squeals.) Thank you!

She kisses YNs cheek which made him blush happily again.

YN: 'Twice kiss in one day. Take that jimbo!'

Krel: I can't believe you all came to help us.

Aja: We don't know what to say.

Toby: Aw, it's nothin'! The only way to survive all of Arcadia's weirdness is if you-

Eli: -Stick together! Yeah! High-five! Ha.

This became awkward until Aja gave him a high five and everybody went back home.

Time skip

At home, krel is practicing with guitar music playing until zadra arrives and catches her breath.

Krel: Zadra? Where's Luug?

Zadra: Retrieval ray retrieved.

He hears Vex screaming and Krel went outside only to see Vex arrives with Buster holding the object Krel needs.

Krel: Is that ?

Vex: Yes! Next time, you two may venture on the quest yourselves. And good luck retrieving the retrieval ray out of that thing's mouth.

Zadra: We tried everything.

Krel quickly obverse and notice Buster is copying Luug. So he decided to give it a try by starting with Luug.

Krel: Luug, drop the ball.

Luug drops the ball and barks.

Krel: (Smiles.) Who's a good boy? Yes, you are! Yes! Yes, you are! (To Buster.) Now your turn.

Buster drops the object which made the Akiridion adults embarrassed and frustrated. Meanwhile in the mother ship, Aja and YN arrive to the controls.

YN: Aja, you sure about this?

Aja: I am. I have to know.

YN: Okay, but you don't have to do this alone, Aja.

Aja: Thanks, YN.

They arrive to meet Mother.

Mother: [Good evening, my royal. Good evening, YN LN.]

Aja: Mother, can you please access the royal records?

Mother: [What would you like to see tonight? Your parents' marital ceremony? Their coronation? Oh, I might suggest your fifth birthday.]

Aja: No. Show me everything on the destruction of planet Voltar.

Mother: [Are you certain, my royal? You may not like what I have to share.]

Aja: I don't have to like it. I just need to know the truth.

YN: Better to face the pain than to avoid it. Otherwise, how can we learn the truth?

With that, mother shows them the destruction of planet Voltar.