The Supergirl-Batgirl Plot is a Superman/Batman team-up story published in Worlds Finest 1941 #169 (September 1967). Written by Cary Bates and illustrated by Curt Swan, it is noteworthy for featuring the first Supergirl/Batgirl team-up, only eight months after Barbara Gordon's debut (in Detective Comics #259). This is, in fact, Batgirl's third appearance.
As patrolling the region between Gotham City and her college town, Supergirl happens upon a space rift and is attacked by a mysterious, disembodied giant hand. She is still struggling against the hand when Batgirl shows up and tries to release her. The strange hand also grabs Batgirl, but a combination of Batgirl's chemical bombs and Supergirl's heat vision appears to blow the hand up.
Kara and Barbara greet each other for the first time. Nonetheless, something appears to have happened to them after their first meeting. Suddenly, both heroines seem to resent Superman and Batman, and start to scheme their downfall.
What has happened to both heroines? Are they being somehow influenced? Or is someone behind their changes?
- Added Alliterative Appeal: A narration box calls Black Flame and Catwoman "the captive crime-chicks".
- All Your Base Are Belong to Us: Batgirl strips off everything from the Batcave while Batman and Robin are away. Meanwhile, Supergirl steals the whole Fortress of Solitude.
- Antagonist Title: Supergirl and Batgirl are scheming against Superman and Batman. Or so it seems...
- Bound and Gagged: Subverted. Superman and Batman are led into a cave where Kara and Babs are supposedly held captive. They find both heroines shacked to two chairs, but it is soon revealed they are lifelike dummies.
- Brought Down to Normal: Mxyzptlk's magic switches Superman's powers off and on at the most inopportune times.
- Calling Card: When Robin and the Batplane disappear, Batman finds a Bat-compact lying on the ground. He quickly deduces it was intentionally left by Batgirl to taunt him.
- Convection, Schmonvection: Robin is thrown into an atomic reactor, but he is hauled out of there by Batgirl. Since his body does not touch the flames, he is completely unaffected by the searing heat or the lethal radiation.
- Continuity Nod: Black Flame was an enemy fought by Supergirl in Action Comics #304.
- Crazy-Prepared: Batgirl steals everything from the Batcave, but fortunately Batman had his Batplane parked on a concealed runway outside the cave...meaning that, in the event that someone finds and loots his super-secret base, he has an extra backup super-secret base.
- Damsel out of Distress: Right when Superman and Batman are arriving to rescue the real Supergirl and Batgirl, Kara and Babs show up, destroy the trap set up for both male heroes, and explain they have freed themselves after spending several days imprisoned in another dimension.
- Doing in the Scientist: As impersonating Supergirl/Black Flame and Batgirl/Catwoman, Mxyzptlk and Batmite must pretend their reality-warping powers have some scientifical basis; so that "Black Flame" claims she drank a super serum to gain powers and used a mind-control ring to confuse Superman, and "Catwoman" states Batman's weird behavior was induced by a special brand of catnip.
- Engineered Heroics: As posing as Supergirl, Mxyzptlk takes Superman's powers away when he is trying to prevent a building from collapsing, so "Supergirl" can show up and save the day.
- Evil Is Deathly Cold: The ghostly hand which captures Kara and Babs feels unbearably cold. Supergirl comments its overpowering glacial aura is so intensely cold it's even making her -who routinely flies through the void of space- shiver.
- Expo Label: In Gotham, there is a billboard placed right to an atomic reactor, which helpfully reads "Danger - Atomic reactor".
- Giant Hands of Doom: Mr. Mxyzptlk and Batmite create a giant spectral hand to grab both Kara and Babs and drag them into another dimension.
- God in Human Form: Mxyzptlk and Batmite, two reality-warping imps from another dimension, shapeshifting into one Kryptonian female and one human woman.
- Green-Eyed Monster: Subverted. Apparently, Supergirl and Batgirl have gotten sick of living in the shadow of Superman and Batman, for which they have decided to humiliate them and take them down. Then it is revealed that Mr. Mxyzptlk and Batmite are playing a prank on everybody.
- Intangibility: When Supergirl charges at the mysterious giant hand menacing her, she flies through it.
- Just in Time: When a crook dumps Robin into a factory chimney, Batgirl suddenly shows up and hauls him back to safety right before he touches the flames.
- Karma Houdini: After keeping Kara and Babs trapped for days while they are trolling Kal and Bruce, Batmite simply leaves, whereas Mxyzptlk is forced to leave without his money bet (which he finds merely annoying).
- Kryptonite Factor: Superman believes he cannot be harmed by a meteor thrown by Supergirl until his X-Ray Vision tells him there's Kryptonite inside the rocky outside. The fat that Supergirl was not harmed by the Green-K clues him in that Kara is a pretender.
- Kryptonite Is Everywhere: Supergirl has no trouble finding a Kryptonite meteor encased in a shell of normal rock to throw at Superman. Of course, given who she really is, Supergirl could simply wish it into existence.
- Latex Perfection: Black Flame's full-head Supergirl mask completely fools Superman, even though he should know his cousin is shorter.
- Lovely Angels: Supergirl and Batgirl meet each other and team up for the first time:Supergirl: "It just took a little teamwork to accomplish our goal, Batgirl"
Batgirl: "Right, Supergirl! We make a great twosome!"
- Meteor-Summoning Attack: The duel between Superman and the fake Supergirl revolves around them tossing meteors at each other.
- Mugging the Monster: As Bat-mite is posing as Batgirl, a crook waves a gun at "her". Of course, a firearm wouldn't frighten Batgirl, let alone a reality warper extra-dimensional imp.
- Mythology Gag: Catwoman's Batgirl mask has curly red locks attached to the back, a nod to Barbara's mask in Batman (1966).
- No OSHA Compliance: Batman and Robin corner a crook right next to an atomic reactor. For some reason, said reactor has an opening on the top of the chamber, with no shielding whatsoever. There is not even a railing around the open pit.
- Offscreen Moment of Awesome: Supergirl and Batgirl spends days surviving and fighting their way through a parallel dimension until they manage to breach the dimensional barrier and fly back into their universe... and readers only get to hear about it.
- Pet the Dog: After having plenty fun at everybody' expense, Batmite tricks Mxyzptlk into returning his dimension, fixes the whole mess they caused and leaves on his own.
- Pose of Supplication: Batman is about to attack a crook who is holding Robin hostage when Batmite sneakily influences Batman into falling to his knees and pleading for Robin's life.
- Pre Ass Kicking One Liner: Batgirl -or, better said, Batmite- is not impressed by a crook's threats:Crook: "You shouldn't have got in the act, sister!"
Batgirl: "Don't pull guns on a gal with a brown belt in Judo... Or you'll get a different kind of belt!"
- Put Their Heads Together: Variant. During a brawl, Batman punches a crook, whose head hits his partner's when the man falls backwards.
- Second Super-Identity: Since Batman does not yet know Batgirl's real identity, Batmite tries to trick him into believing Batgirl is Catwoman's second secret identity. Nonetheless, Batman is not fooled because both women have different eye colors.
- Schmuck Bait: When Mr. Mxyzptlk declares he has won their bet and demands the prize money, Batmite writes a check and hands it over to Mxy, saying he has signed it with his real name. Puzzled, Mxyzptlk reads "Klt Pzy Xm"...and he realizes he has been tricked into saying his name backwards right before being forcefully and automatically returned to his own dimension.Mr. Mxyzptlk: "You owe me a dimensional check for 100 magic units! Your hero and his partner lost!"
Batmite: "Oh, all right! Here...I signed it with my real name...the one I use in my own dimensional world!"
Mr. Mxyzptlk: "Hmm...Your name is... Klt Pzy Xm? Yaaa! It's my name...in reverse! Whenever I say it backwards, I'm automatically returned to my own world! You tricked me!"
- Shapeshifting Trickster: All Imps from the Fifth Dimension can alter reality and change shapes at will...and all of them are pranksters and tricksters who love having fun at someone else's expense. Here, Superman's foe Mr. Mxyzptlk and Batman's fan Batmite transform into Black Flame and Catwoman to prank Superman and Batman as impersonating Supergirl and Batgirl.
- Spotting the Thread: Superman realizes that he is fighting an impersonator when "Supergirl" is knocked out by a meteorite after failing to be hurt by Kryptonite. Similarly, when Batmite tries to fool Batman into believing Batgirl is Catwoman's second identity, Batman points out that Batgirl's eyes are blue, whereas Catwoman's are green.
- Superdickery: The cover◊ features Supergirl and Batgirl gloating about ruining both Superman and Batman's lives. The scene happens in the inside, but both "women" turn out to be Mr. Mxyzptlk and Bat-mite impersonating Kara and Babs.
- Super Serum: Subverted. When Superman unmasks the imposter Supergirl, he finds out it is Black Flame, one of his cousin's Rogues who had been depowered a while back. Superman asks how Black Flame got her powers back, and the woman claims she invented a super serum which gave her most of them back but trading her invulnerability to nearly everything for invulnerability to Kryptonite. However, it is soon revealed that Mr. Mxyzptlk was impersonating Black Flame, and the "super serum" was nothing but humbug.
- Tempting Fate: The story begins with Supergirl commenting on her uneventful morning patrol right before running into a giant energy hand.Supergirl: "It seems pretty peaceful around here today— so far no emergency has come up that requires my super-powers! ... Maybe I spoke too soon! What in the name of Krypton is that?"
- Time Capsule: A time capsule filled with Superman, Batman and Robin memorabilia is launched into space, where it will remain into orbit around the Earth for five hundred years so future people know about the world's greatest heroes.
- Trapped in Another World: Supergirl and Batgirl spend several days trapped in a pocket dimension until they manage to break through.
- Villain Has a Point: As impersonating both heroines, both imps watch a feature showing a time capsule being launched so people know about Superman, Batman and Robin, and think it is unfair that even the male heroes's male sidekick gets more acknowledgment that their female counterparts whose hard work is ignored.
- Villain Team-Up: It looks like Supergirl and Batgirl are teaming-up to take Superman and Batman down. However, Batman unmasks both women, who turn out to be Catwoman and Supergirl's enemy Black Flame. But then the real Supergirl and Batgirl arrive just in time to save both heroes from a dimensional trap, and both villains transform back into their real selves, Mxyzptlk and Bat-Mite. It turns out both Imps were teaming up to see if they could trick Superman and Batman into trapping themselves in another dimension.
- Wouldn't Hit a Girl: In contrast to his usual self, Batman is reluctant to fight Batgirl because he does not want to hit a woman.Batman: "How do you want to fight? I can't use my fists on a girl!"