Fresh off of successfully defeating a giant turtle, Stargirl, S.T.R.I.P.E., Supergirl, and Green Lantern are sucked down into a vortex over the North Pole and crash-land in Skartaris, a land in the center of the earth. The group meets Travis Morgan, a former Air Force test pilot who is helping defend the people of Shamballah from a warlord magician named Deimos and his Dino-Troopers. Morgan explains that he's trying to keep Deimos away from the Great Stone and that he had his daughter Jennifer magically draw the Javelin to Skartaris. Since Deimos has started using advanced technology, Shamballah is all that's left to stand against him.
Meanwhile, Deimos interrogates a messenger and his allies, Silver Banshee and Metallo, realize they've run into Supergirl...
Tropes:
- An Arm and a Leg: Metallo is forced to rip out one of his arms after Supergirl inflicts too much damage with Stargirl's staff.
- Bad Boss: Deimos threatens a messenger trying to give him vital information, then vaporizes him after he spills the beans.
- Big Badass Battle Sequence: Deimos's army attacking the people of Shamballah.
- Bring It: Travis interrupts Deimos preying on Stargirl, challenging him to a fight. Deimos happily obliges.
- Brought Down to Badass: Even though Supergirl's powers aren't working, that doesn't stop her from grabbing a sword and leaping into the fray.
- Cat Girl: Shakira, a woman who can shapeshift into a panther.
- Crazy-Prepared: Metallo was wired to short-circuit if he attempted to tell the League about Grodd's new Secret Society.
- Didn't See That Coming: Green Lantern over encountering Silver Banshee on the battlefield.
- Disney Villain Death: At the end of his duel with Morgan, Deimos tries to thrust a sword at him, only to miss and accidentally fall off the staircase to the surface world they were on; the audience doesn't see or hear him hit the bottom of the dark pit he falls down.
- The End... Or Is It?: Skartaris is safe and cutoff from anyone else looking to claim the kryptonite, but Green Lantern and S.T.R.I.P.E. fear the League's got a new problem on their hands.
- Expy: Deimos' character design and voice are clearly modeled after Christopher Lee.
- Fire-Forged Friends: At the start of the episode, while dealing with the Kaiju, Stargirl is absolutely frustrated that Supergirl is purposely stealing the spotlight. After their adventure in Skartaris, where the two girls were on more even footing due to Supergirl being disconnected from the sun's rays, the two end up bonding and trading stories about the curfews enforced on them.
- Funny Background Event: As Morgan is explaining who Deimos is, Supergirl is trying to lift a rock hardly bigger than herself.
- Germans Love David Hasselhoff: in-universe, Supergirl is apparently popular in Japan — she has a whole convention going on there in her honor.
- One would think that Stargirl and S.T.R.I.P.E. would be popular in Japan given they are basically a Magical Girl and a Metal Hero, respectively. Then again, mecha are so last year.
- Godzilla Threshold:
- Jennifer explains she brought the four heroes to Skartaris, saying the situation is just that dire. What army they have is just too outmatched by the advanced technology being supplied to Deimos.
- The "Great Stone" is believed to be a magical curative, but the locals freely acknowledge it just as easily kill a given person. Speaking from personal experience, Machiste says only the most desperate would attempt exposing themselves to it.
- Goofy Print Underwear: The tiny red hearts on Travis Morgan's loincloth indicate that it was made from the remains of one of these.
- Hypocritical Humor: After dealing with the Kaiju, Green Lantern starts to lecture Stargirl for grandstanding, only for Stargirl to point out the incredibly blatant Supergirl convention happening down the street and how Supergirl herself is now signing autographs for children.
- I Choose to Stay: Travis has no issue with the League permanently closing the portal, saying he has a home and loved ones in Skartaris.
- Irony: When Deimos asks if he recognizes the crude drawing of the Superman shield, Metallo smirks and says he most definitely does.
- It's Personal: Metallo is fairly indifferent to Supergirl, until she starts inflicting some damage and gives him more trouble than he anticipated.
- Kaiju: The giant turtle attacking Japan seems to be channeling this.
- Little Girls Kick Shins: A chubby Japanese fangirl kicks Stargirl in the shin for badmouthing Supergirl.
- Men of Sherwood: Travis Morgan's army in the subterranean kingdom of Skartaris put up a good fight against technologically superior forces and it's made clear that while they probably wouldn't have won without the heroes' help, both their leaders and the average soldiers would have still put up a pretty good fight before going down.
- Mythology Gag: The giant turtle having orange hair. It's a nod to Jimmy Olsen's Silver Age transformation into Turtle-Man.
- Not Helping Your Case: In response to GL wanting a word with her about grandstanding, Stargirl complains that Supergirl stole her thunder. That's the kind of mindset he's complaining about.
- "Not So Different" Remark: In the last scene, Supergirl and Stargirl share stories of the different ways their respective authority figures kept telling them what to do.
- Nubile Savage: Pretty much everyone in Shamballa.
- Open Mouth, Insert Foot:Stargirl: (sees rebels of Shamballa training) Geez, you call that an army?Morgan: Most of these folks have lost everything to Deimos, so, you know, feel free to dump on them.(Green Lantern and S.T.R.I.P.E. glare at Stargirl who winces)
- Power Limiter: Because of the limited sunlight in Skartaris, Supergirl is brought down to what she describes as "half-strength", though it seems to be even less than that. As it turns out, this is a good thing — otherwise, she would have been dead several times over from kryptonite exposure. It even lets her get close enough to pry Metallo's kryptonite battery from his chest.
- Replacement Flat Character: Stargirl is basically Supergirl when she first appeared in Superman: The Animated Series: inexperienced, brash, and wanting a piece of the action.
- The Rival: Stargirl and Supergirl, until they start to become Fire-Forged Friends.
- Sacred Hospitality: While requesting their help, Travis treats the Leaguers to the best dinner he can offer. He's only sorry he can't provide his guests even more.
- Shapeshifting: When Shakira arrives to report Deimos' arrival, she enters the temple as a black panther before immediately shifting into the form of a woman.
- Shout-Out: The giant turtle resembles Gamera.
- Shut Up, Hannibal!:
- When Supergirl can't run anymore, grabbing a dagger from a fallen Skartarian before Metallo catches up to her.Metallo: You lied, little one. I can see the illness creeping over you. You have none of Superman's strength.
Supergirl: But I got brains! [cuts the kryptonite out of his chest] - After his sword is destroyed by Travis, Deimos opts to be spiteful.Deimos: You think you've won? No freedom-loving warlord will ever unite the lands and bring peace. Justice? A foolish dream.
Travis: Maybe so, wizard, but it's the one dream worth fighting for.
- When Supergirl can't run anymore, grabbing a dagger from a fallen Skartarian before Metallo catches up to her.
- So Last Season: When Stargirl tries to gain cred by pointing out her stepfather drives a mecha, the Japanese girl scoffs, "Mecha so last year."
- This Cannot Be!: During dinner, S.T.R.I.P.E. admits he's still struggling to process being in a primitive world in the center of the planet.
- This Is Gonna Suck:
- Shakira reports to Travis about the situation, saying, "Deimos is here. It's the end."
- When Green Lantern says he intends to have J'onn probe Metallo's mind, S.T.R.I.P.E. suspects they have a big problem on their hands.
- Too Dumb to Live: Stargirl constantly badmouthing Supergirl in the Javelin. S.T.R.I.P.E. points out the foolishness of talking behind the back of someone with super hearing.
- Villain Team-Up: Grodd's operation cut a deal with Deimos: they'll help him conquer Skartaris, and he'll let them have the very large chunk of kryptonite.
- Wham Shot:
- Deimos's military advisers revealing themselves to be Metallo and Silver Banshee.
- The fabled "Great Stone" is a massive piece of kryptonite.
- What the Hell, Hero?: In The Teaser, Green Lantern intends to read Stargirl the riot act for grandstanding and ignoring orders.
- White Magician Girl: Jennifer, who has enough power to draw down a starship and summon a giant phoenix to mow down enemies.
- Wrong Assumption: Because the "Great Stone" has a reputation for being potentially deadly, Travis assumes Deimos wants it as part of subjugating Skartaris. Deimos actually has no personal interest in it whatsoever, instead having made a deal to hand it over to Metallo and Silver Banshee once his rule is assured.
- You Have Outlived Your Usefulness:
- When a mook returns having failed to subdue the freshly arrived Leaguers, Deimos demands whatever information he can provide about what happened. The moment the mook provides that (a crude drawing of the Superman shield), Deimos executes him.
- The moment before Metallo decides to rat on who he's currently working for, an outside source activates an electric pulse in his body and renders him comatose.
