DC Super Hero Girls: Super Hero High, on Boomerang & Cartoon Network
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Caution: spoilers.

This special takes place between the first and second episodes of season 2 of the webseries DC Super Hero Girls. It originally aired on Boomerang in March 2016, and on Cartoon Network in April 2016. However, I didn't see it until May 2017, on CartoonNetwork.com. (It's kind of annoying I didn't know it would be on Boomerang, since I get that channel, and therefore could have watched it. I thought it was only going to be on Cartoon Network, which I don't currently get. And the website says it aired in January 2017, which I assume is when it was uploaded to the site. So I'm finally watching it more than a year after it aired on TV, and like four months later than I could have seen it online, if I'd thought to look for it sooner. Still, I'm happy that I can watch it online.) In 2018, the special was released as a bonus feature on the DVD movie Legends of Atlantis.

Anyway, I should say that in the second season premiere of the webseries, Wonder Woman was, like, Skyping with Supergirl, trying to encourage her to choose to attend Super Hero High, rather than any of the other offers she's received from various schools (some on other planets). We also see in that episode that Supergirl is nervous, because she has trouble controlling her super powers. But she chooses Super Hero High, anyway. Now, this special starts with several of the current students battling Killer Croc, while waiting for Supergirl to arrive at school. Meanwhile, Supergirl is still in Smallville, where she's been living with Jonathan and Martha Kent (Dean Cain and Helen Slater) for like the past month. She's still nervous about her lack of control, because unlike her famous cousin, Superman, who had years to learn to control his powers before going to school (let alone becoming a super hero), she's only had a few weeks, since arriving on Earth. But her "Aunt and Uncle" Kent are very encouraging.

So, Supergirl flies to the school, and crashes into the cafeteria, causing quite a bit of damage. Luckily, Principal Waller isn't phased, and just calmly assigns students to take care of repairs. Oh, and incidentally, this special is the first time we actually hear Vice Principal Grodd speak. (He's voiced by John DiMaggio, who also voices the gym teacher, Coach Wildcat.) But while everyone remains excited to meet Supergirl, Wonder Woman's own excitement begins to waver when Principal Waller refers to Supergirl as a "one of a kind catch" for Super Hero High, which is what she previously said about Wonder Woman when she was new to the school. Meanwhile, this is Barbara Gordon's last week working in the school's IT department. And her father, Commissioner Gordon (Tom Kenny), is glad that she's not a super (and won't be around them much longer), because of how dangerous superheroes' work can be.

Anyway... I don't want to spoil too much, but there's just so much going on. Um... we meet the school librarian, Granny Goodness. And Principal Waller shows Supergirl the room where the boom tubes are located. (For those not familiar, they're kind of like transporters to different planets.) But Waller is the only person with access to that room. Immediately after that, the Metropolis Junior Detective Society shows up. They're a school club first seen in a season one episode of the webseries, where it included Bumblebee, Hawkgirl, and Barbara. But here, instead of Barbara, it includes Flash, who was in the Science Club in that episode. Anyway, they're currently investigating various suspicious activity around the school, including attempts to break into the boom tube room. And before long, a clue (analyzed by Poison Ivy) suggests Vice Principal Grodd might be the culprit. Also, Harley Quinn tells Supergirl about a rumor that Grodd used to be a supervillain, before Waller got him released from prison to work at the school. Later, Supergirl has a talk with Barbara about her continued anxiety involving her super powers. So, Barbara tries to help train her to use her powers. (At one point, Barbara has a line about "not apologizing for learning" which I'm sure I heard sometime in the webseries, before this. But it's possible it was a clip taken from this special, I don't remember the exact context.) Then there's a training montage with some background music that sounds reminiscent of "Eye of the Tiger," which I found pretty amusing. And then Barbara asks Wonder Woman to help with Supergirl's training, which puts a quick and tidy end to Wondy's jealousy of Supergirl.

And then... the plotlines all start tying together. We learn who the real culprit was in the Detective Society's investigation, and it's not Grodd. I won't reveal who it was, but it shouldn't come as a surprise to anyone who knows anything about DC comics. I will say that in order for the villainous plot to unfold, Supergirl has to make a really foolish error in judgement, but it's something that never would've happened if not for something Cheetah does (surprise, surprise). But anyway, it all leads to Supergirl and Barbara needing to team up to stop the villains... after Supergirl convinces Barbara to become a superhero, herself. (And it will come as a surprise to no one that her superhero identity is Batgirl... a name which, even if she weren't such a well-known character, was jokingly foreshadowed earlier in the special. But there's also an amusing gag that happens with Barbara's voice when she first calls herself "Batgirl.") And then all the heroes get in on the action, in a pretty awesome battle. Even Grodd helps out. And finally, Batgirl becomes a student at Super Hero High. (Her dad, of course, is both proud and nervous.)

So, a lot of stuff that happened (or rather, will happen) in seasons 2 and 3, as well as the movie Hero of the Year, are explained in this special. I still think it would have been nice to have seen it before seeing those things, but despite my earlier complaints, part of me is actually kind of glad not to have seen the special until I had some foreknowledge of various things. I guess. Either way, it was pretty fun.