Mordred uses his magic to remove all adults from Earth, leaving only children. Morgaine le Fey uses her magic to turn Superman, Batman, Green Lantern and Wonder woman into children in order to change things back.
This episode includes examples of:
- Adults Are Useless: According to Mordred anyway. However, it's Morgaine le Fey who helps the Justice League get back to Earth to fight him and several children admit out right that they miss their parents.
- Age Without Youth: Once Mordred breaks Morgaine's spell of eternal youth, he ages to the appearance of what you'd expect someone several centuries old would look like. And because he now only has eternal life instead of eternal life and youth, his mother still has to take care of him.
- Agony of the Feet: Superman uses his heat vision on the bottom of an enlarged Mordred's Giant Foot of Stomping, but it doesn't slow him down for long.
- Amulet of Concentrated Awesome: The Amulet of First Magic.
- And I Must Scream: Mordred's fate. He had eternal youth, but now he only has eternal life.
- Badass Adorable: Superman, Batman, Green Lantern and Etrigan.
- Little Miss Badass: Wonder Woman.
- Batman Gambit: How Batman gets Mordred to defeat himself. He mocks Mordred for being a Momma's Boy, accuses him of liking it and proposes that if he really didn't, he wouldn't allow himself to look like a child forever. Mordred ages himself up. The expected happens.Superboy: Some king.
Wondergirl: Im not impressed.
Batboy: Whatd you expect? Hes a boy, doing a mans job.
Mordred: You dont know what its like, being stuck as a kid!
Batboy: (smirking) Since you got all that power, you couldve been a man anytime you wanted! I think youre too chicken to grow up!
Kid Lantern: Yup! Biiiiig chicken, thats what you are!
Batboy: (full-on grinning at this point) Face it, Precious; you like being a little Momma's Boy!
Mordred: Ill show you! ILL SHOW YOU ALL!
- Betrayal by Offspring: Morgaine by Mordred.
- Black and Nerdy: John spends some time geeking out about what he can make with his ring.
- Boring, but Practical: When Kid GL was trying to decide what weapon to form to fight the golems, from a laser cannon to a missile launcher, Batboy angrily tells him to just pick something already as the golem was getting closer. He settles with knocking it away with a giant boxing glove.
- The Caligula/Overlord Jr.: Mordred.
- Captain Oblivious: Superman.
- Cool Shades: Green Lantern had bad vision as a child, and needs these.
- Creepy Child: Mordred.
- Curb-Stomp Battle: The League just finishes wrapping one up against a gang of C-list villains before the plot begins.
- Cute Bruiser: Superman.
- Dark Shepherd: How Superman gets some kids to stop fighting and listen to him: he shoots his heat vision at them.
- Did Not Get the Girl: Sadly after a huge amount of Ship Tease, Batman still pushes Wonder Woman away.
- Don't Tell Mama: How Wonder Woman gets the whole populace of children to do what she says or else.
- Enemy Mine: Morgaine Le Fay helps the Justice League get back to Earth and defeat Mordred...mainly because he stabbed her in the back when he cast his spell.
- Evil Brit: Mordred. Morgaine le Fay is also evil, but willing to work with her enemies in order to work against her son.
- Foreshadowing: At one point, Mordred rubs his face in frustration. For a split second, this makes him look similar to his appearance by the end of the episode.
- Four-Temperament Ensemble: John is sanguine, Diana is choleric, Bruce is melancholic and Clark is phlegmatic.
- Fountain of Youth: The heroes have to accept Morgaine's help to turn them temporarily into children to help them get back to Earth.
- Fun Size: The heroes are turned into kids.
- Genre Blind: Not that it matters too much. The JL managed to trick Mordred into doing the one thing that will turn his own magic against him: aging himself up.
- Get A Hold Of Yourself Man: Copperhead needs some sense smacked into him by Cheetah when he believes the adults enter Hell.Copperhead: "It was Judgement Day! And we got sent to the Bad Place! The Bad Place!!!"Cheetah: (smacks Copperhead) "Snap out of it, Copper!"
- Guile Hero: About the only thing Batman has in child form are his brain and child-sized bat-gadgets.
- Hoist by His Own Petard: Mordred ages himself up to an adult to prove that he can, which causes his magic to send him away to the dimension the rest of the adults are sealed in, among other things.
- Humongous Mecha: Green Lantern makes one.
- Imagination-Based Superpower: Aged down, John finds it much easier to use his power ring, but his imagination goes into overdrive and he can't decide what to make first. He is also more easily distracted.
- Immortal Immaturity: Mordred as a side effect of not maturing for centuries.
- Jerk with a Heart of Gold: Bruce's normal personality is softened. He keeps his distance from the other League members as usual, but is the only one who doesn't boss the normal children around (even Clark does!), and he is the first to tell everyone not to hurt Etrigan.
- Kids Are Cruel: Some children have great fun using a guillotine. John briefly ponders using a giant lawn mower to chew up Mordred, and even Clark uses his heat vision to make boys listen to him (though he does aim away from them).
- Living Toys: Mordred animates some action figures to act as his guards.
- Loophole Abuse: Mordred's spell banished all adults to another dimension. How do the League combat him? By having Le Fay temporarily turn them into kids in order to get back to Earth.
- Magic Pants: The heroes' outfits and equipment shrink to fit their smaller bodies, and grow back to normal size at the end.
- The Mind Is a Plaything of the Body: The de-aged heroes act like eight-year olds.
- Momma's Boy: Mordred. He does not like being reminded of this.
- My Beloved Smother: Morgaine le Fey.
- Mythology Gag: When John creates his second (much cooler) glasses, they look nearly identical to the mask fellow Lantern Kyle Rayner wears in the comics.
- Not Allowed to Grow Up: Mordred is still a child despite being centuries old. Because if his mother allowed him to age, he'd age forever. Which is why he decides to backstab his mom — he'd gotten fed up with the constant failed plots and wanted to start ruling already.
- Plot-Relevant Age-Up: Played straight for Mordred; this allows him to be defeated.
- Ship Tease: Between Bruce and Diana, as usual.
- Spanner in the Works: The little redhead girl with the bunny doll. Her understandable fearfulness and crying distracts Mordred from killing the Justice Kids.
- Team Mom: Wonder Woman, of the extremely bossy kind.
- Teenage Wasteland: The world becomes this with Mordred's no-adults spell put into place.
- There Are No Adults: Courtesy of Mordred's spell.
- There Is No Kill Like Overkill: Using a guillotine to remove the helmet from an empty suit of armor.
- Victory Is Boring: Briefly implied for Mordred; before the Justice Kids show up, he's trying to act like an "adult" king the best he can, grudgingly using his magic to grant the wishes of any kid that approaches his throne.
- Villainous Breakdown: Guess.
- Wise Beyond Their Years: All four Justice League members are technically this, as they have the physical bodies of their child years with the memories of their adulthood. But they also have their childhood personalities.