The Justice League reluctantly teams up with the Secret Society to repel Darkseid's full-scale invasion of Earth. As the League and Secret Society members battle the Apokolips fleet across the planet, Superman, Batman, and Lex Luthor take on Darkseid.
!!This episode includes examples of:
* AndTheAdventureContinues: The TropeNamer
* BackForTheFinale: [[spoiler:J'onn]]
* BadassBoast: Darkseid, natch.
-->"I'm more powerful than I've ever been and the last time we met, you barely managed to hold your own."\\
"Super or otherwise, you're merely a man. And I am a god!"
* BookEnds: Batman was the first hero in the DCAU franchise to appear onscreen, and he's the last one seen in this episode. Also, Kevin Conroy had the second line in the first ''BTAS'' episode "On Leather Wings" (as an incidental character) and gets the second-to-last line here.
** Like the first episode of this series, this episode sees the team needing to defeat an alien invasion.
* [[spoiler:DisneyVillainDeath:]] [[spoiler:Darkseid and Lex Luthor take hold of the Anti-Life Equation and disappear in a flash of light. WordOfGod says they end up in the Source Wall. Darkseid gets better though, as seen in the New 52's ongoing ''Justice League Beyond''.]]
* CallForward: Superman's quip about Batman getting soft in [[WesternAnimation/BatmanBeyond his old age]].
* CurtainCall: Pretty much the entire team running/flying down the steps of the Metro Tower. The groups are broken up into different teams from the comics before concluding with the show's Big 7.
* DidYouJustFlipOffCthulhu: Batman manages to almost knock Darkseid down ''and'' manages to avoid his Omega beams.
* FateWorseThanDeath: The Agony Matrix.
-->'''Darkseid:''' Imagine the worst pain you've ever felt in your life, times a thousand. Now imagine that pain continuing forever. Oh, that's right. You don't have to imagine.
* HostileTerraforming: Darkseid's army drops magma towers in order to create fire pits ("Apokolips on Earth" as Steel puts it).
* IronicEcho: "Let's go."
* MegatonPunch: Superman sends Darkseid flying across Metropolis.
* MercyKill: In response to Superman surviving the effects of the Agony Matrix, Darkseid says this:
-->"Still alive. You impress me, Kryptonian. More... your valor has touched my heart. Oh yes, there is still some small part of me that knows mercy. I will end your pain with something special I've been saving for just this occasion. ''(takes out a Kryptonite knife)'' I'm going to carve out your heart and put it on a pike in my throne room."
* MercyLead: Batman's five minute head start.
--> '''Superman:''' ''(angrily)'' C'mon, it's Lex flippin' Luthor!
* SaveTheVillain: Batman saves Lex after Darkseid blasts him off the top of the Daily Planet building.
* TemptingFate: When Luthor bets that Darkseid won't notice Superman, Batman and himself battling atop of the Daily Planet.
* WorldOfCardboardSpeech: TropeNamer
-->'''Superman:''' That man won't quit as long as he can still draw a breath. None of my teammates will. Me? I've got a different problem. I feel like I live in a world made of cardboard, always taking constant care not to break something, to break ''someone''. Never allowing myself to lose control even for a moment, or someone could ''die''. But you can take it, can't you, big man? What we have here is a rare opportunity for me to cut loose and show you just how powerful I really am.