If the plan for "Supergirl" was to start with the cute, fun stuff and gradually go full nerd, it seems to be working. A jam-packed episode made room for a Legion ring, Kelex, a Quidditch joke, and a truly sick burn about Vista. What's more impressive is that they managed to pair that sort of gleeful geekery with some well-acted, deeply felt storytelling that shook up the "Supergirl" status quo. That's a lot to accomplish in an hour -- even without a quick jaunt to the Fortress of Solitude.
Still, all the sub-plots tied into the main event of the evening: the arrival of the artist-formerly-known-as Brainiac 8. When CatCo gets "gifted" a USB drive filled with the dirtiest secrets of the users of an Ashley Madison-esque site, Cat asks Siobhan to melt the thing in the microwave, rather than expose the people who use the service. That prompts a not-so-nice reaction from the hacker behind it, a mysterious "evil blonde computer face" who turns out to be Indigo. She wreaks havoc on the city, highlighting the difficulty that the denizens of National City have communicating with each other and even telling the truth.
The first, and simplest, story on that list is that of Siobhan, who goes from highly competent mean girl to stuttering mess as soon as the adultery-site gets mentioned. A few minor outbursts later and Winn somehow gets her to tell him what's wrong: her dad, who once promised he was done cheating, is on the list. Winn finds it in him to be generous to a woman who has been nothing but cold and calculating since she started at CatCo, and to make a long story short, she lays a great big kiss on him and pushes him into an elevator. It's an unexpected development, and one that (casting spoiler) seems likely to get a lot more interesting, but of the threads running through "Solitude," it's the least interesting.
Luckily, nearly everything else, from the personal stuff to the great big battles, mostly fires on all cylinders. Alex is still dealing with the guilt she feels about allowing H'annk to lie for her, particularly given that his taking the blame has driven Kara out of the DEO (to both her and the agency's detriment). And even though H'annk and Alex's timely arrival after Indigo's first appearance seems to have saved the lives of Kara's friends, she still wants to go it alone.
That's a problem, because Team Supergirl is having some trouble. First Winn gets spirited away to learn some crazy alien code for the DEO, leaving JimmyJames and Kara to fend for themselves. But James has problems of his own to deal with, namely that his refusal to tell Lucy Supergirl's identity only increases her understandable jealousy of the Maiden of Might -- particularly when he forgets to show up at a date intended to help solve things. Kara doesn't help matters either: go ahead and file her attempt to remind Lucy what a good guy James is under "well-intentioned but terrible ideas." Gradually Kara realizes that, while it might be fair to put James in a position where he has to lie in order to ensure her safety, it's not fair to do it simply because she wants to keep him to herself.
So James heads off to tell Lucy the truth about his friend in the cape (well, his most recent friend in the cape), but the truth comes too late. Lucy Lane is a very smart woman, and she is done with that nonsense. It isn't about Supergirl at all. It's about Kara. Jenna Dewan-Tatum hasn't had much to do in the series thus far, but she really nails both of her big scenes in this episode, first politely shutting down that supremely uncomfortable scene with Kara, and then calling JimmyJames on his crap like an adult.
With all that personal drama, it might be easy to forget that Kara's got to do battle with a supervillain (and Non's ex, apparently). After Winn heads off to help the DEO, James and Kara make a little trip to the Fortress of Solitude to get some alien intel. While the trip's largely uneventful, it's also undeniably cool to see Kara and Jimmy in the Fortress. The best intel they get, however, comes not from Kelex, but from Lucy.
Indigo, it seems, was targeting a specific General in that website hack, and the chaos was just a smokescreen to hide the fact that the ultimate goal is breaching a nuclear base. So with little to no help or information, Kara heads off to try to stop Indigo before she can literally drop a bomb. It's a great fight, one that Kara's mostly losing, and before she can gain some control, Indigo sends an armed nuclear weapon soaring toward the center of the city. Kara chases it down "like Harry Potter playing Quidditch," but can't re-route it, and with that, she's got to go back to H'annk for help. One disarmed missile later, she's back to kick some Indigo ass--with a lot of help from Winn, who survives a choking to feed Indigo a computer virus and defeat her (at least for now).
So all seems well, but Alex has one more truth to tell. When Kara announces she's coming back to the DEO in spite of her feelings toward H'annk, Alex finally lets it out, confessing to Kara that she's the one that's actually responsible for Astra's death. Chyler Leigh does a terrific job with this scene, which is also beautifully directed -- particularly the shot where Kara grips H'annk's hand as she holds her sobbing sister. It's a dark but nonetheless inspiring moment, showing they're truly stronger together.
Nice ending, but "Supergirl" has one last revelation in store. Non's managed to collect the various pieces of Indigo, and he's going to bring her back. That won't be good. It's an ominous ending for a sad but solid episode that, in spite of its inherent darkness, also managed to be a lot of fun.