Returning home from the other dimension, Batman discovers Owlman had escaped from the holding cell and has been committing crime in Batman's old costume. With his allies now against him, Batman has to the team up with the one person he'd never expect to defeat Owlman... the Joker!
- Achilles' Heel: Owlman is able to subdue the assorted heroes because he got into Batman's computer and found contingency plans on how to deal with them.
- All of the Other Reindeer: Green Arrow pointedly reminds Plastic Man that his assistance is not wanted.
- Batman Gambit:
- Batman tells Joker not to touch the red button on the Batmobile, counting on the fact the Joker will do it anyways. And naturally, said button activates sleeping gas once Joker finally does, which allows Batman to take his Arch-Enemy to the Batcave without compromising its location.
- In order to break the Enemy Mine, Owlman arranged for a Death Trap for Batman and gave Joker the remote control. It works.
- The Cavalry: Turns out, Batman expected Joker to stab him in the back, so he made sure to call in some alternate versions of himself to help in the final battle.
- Chekhov's Classroom: Joker accuses Batman of not being a team player and admits they both only truly trust themselves. Batman later cites this lesson when revealing he got the help of his dimensional counterparts.
- Corrupted Contingency: This episode reveals that Batman has information on his fellow heroes' weaknesses to be used against them in the event they go bad. Owlman uses this information to neutralize and capture the heroes while he impersonates Batman.
- Curb-Stomp Battle: The villains are on the receiving end of this when Batman brings in his counterparts. It gets even worse for the villains once the different heroes are freed.
- Death Trap: Owlman places each of the captured heroes in a custom trap, such as Aquaman being under an intense heat lamp and Green Arrow being tied to a bullseye.
- Don't Explain the Joke: Owlman makes a quip when talking about each custom Death Trap. He's interrupted by Green Arrow, who points out he gets the intended joke.
- Don't Touch That, You Idiot!: Batman's go-to response for when Joker wants to try the car's different buttons.
- Enemy Mine: Joker teams up with Batman because there's only room for one king of crime in Gotham.
- Exact Words: "Traveling alone is a great way to get in touch with yourself. In fact, I really bonded with me, myself, and I."
- Good Feels Good: Downplayed. Joker admits that playing hero was actually fun, but naturally, it didn't make him feel that good.
- "Hell, Yes!" Moment: Aquaman eagerly smiles once hit with water from the sprinklers. He's immediately back to full strength and sets about punching out Black Manta.
- Hero with Bad Publicity: The episode opens with Batman on the run from the police and his fellow heroes. It's only the intervention of the Joker that saves him from the latter.
- I Warned You: Batman kept telling Joker not to touch any of the car's buttons, but he really stressed a particular button be left alone. Joker presses it, anyway, and gets sprayed with Knockout Gas.Batman: Told you not to touch it.
- Knockout Gas: How Batman gets Joker in and out of the Batcave without the clown learning its location.
- Mythology Gag: While masquerading as Batman, Owlman wears the costume Bats wore in his very first appearance in Detective Comics #27.
- "Not So Different" Remark: Before being hauled off to prison, Joker admits this Enemy Mine has made him wonder if he and Batman could've been friends under a different set of circumstances. In his narration, Batman admits it could've been possible, due to his experience with Red Hood in the previous episode.
- The Only One Allowed to Defeat You: "Nobody kills my wingman but me."
- Exploited by Owlman. When he has Batman set up for a trap, he gives the button to activate it to Joker, knowing he’d be all too willing to push it.
- Running Gag: "How does he do that?"
- Villain Has a Point: Batman initially had no interest in teaming up, but Joker reasoned that he'll never be able to beat an Evil Twin that's his physical and mental equal. Joker says Batman needs an edge to win and that a persistent enemy with a history of nearly winning is the best candidate for the job. Batman concedes "an unexpected element" might make the difference.
- Villain Respect: Owlman admits Batman getting the better of the Injustice Syndicate is impressive.
- Villain Team-Up: Owlman recruited Grodd, Clock King, Black Manta, Gentleman Ghost, the Brain, and Dr. Polaris. Owlman points out it was no trouble getting help from villains that hate Batman and his fellow heroes.
- Villainous Rescue: Batman is cornered by the other heroes, only to be saved by his Arch-Enemy. Joker later saves Batman from being run over by Owlman.
- We Will Meet Again: What Owlman promises to Batman before being taken away by the other Batmen. Joker does the same soon afterwards.
- Wham Shot: Batman's mysterious savior being revealed to be the Joker.
- Wrong Genre Savvy: After seeing Batman emerge from the wormhole, Plastic Man is certain that that's how he's always pulling off his amazing feats.
- Year Inside, Hour Outside: Only a mere moment passes in-between Batman seemingly being doused in wax and emerging from the wormhole. He says that this split-second was, from his perspective, actually a week. He spent that time recruiting several Batmen for help.
- Year Outside, Hour Inside: On the run from the police, Batman learns he's actually been gone for three weeks and that his counterpart spent all that time ruining his good name.
