Great Krypton, there are spoilers everywhere in this review, so be warned!
Regular Cast: Melissa Benoist (Kara Zor-El/Kara Danvers/Supergirl), Mehcad Brooks (James Olsen), Chyler Leigh (Alex Danvers), Jeremy Jordan (Winn Schott), David Harewood (Hank Henshaw/J'onn J'onzz), Calista Flockhart (Cat Grant); Guest Starring: Peter Facinelli (Maxwell Lord), Laura Benanti (Alura Zor-El/Astra), Chris Vance (Non), Robert Gant (Zor-El), Daniel DiMaggio (Kal-El). Written by Ted Sullivan & Derek Simon; Directed by Dermott Downs
Based on the classic For The Man Who Has Everything Superman comic book story by Alan Moore, this episode has Non, in an effort to incapacitate Supergirl without killing her (out of respect for his wife and her aunt, Astra), attack her with a creature known as the Black Mercy, which has the effect of taking its victim's most fervent desire and plunging them into that world. In Kara's case, it's to live her life on Krypton, having never lost her parents or the place she grew up. The reason for doing so is so that a massive solar storm can be tied into an enigmatic project called "Myriad," which will allow the Kryptonians to conquer the Earth. With Supergirl out of the way, nothing can stop them (although there's supposed to be this other Kryptonian in Metropolis...just sayin').
Initially, Kara knows this sudden life on Krypton can't be real, but as she's reunited with her mother and father, and her 13-year-old cousin, Kal-El (that same Metropolis Kryptonian, only this is the younger version), memories of her life on Earth start to fade away.
Back in reality, James and Winn, who discovered Kara's unconscious body in her apartment, contacts Alex who brings all of them to the DEO. Attempts are made to remove the Black Mercy, but Kara's body begins to convulse violently in response (think of the facehugger being removed from its victim in Alien) and all efforts are stopped. Alex confronts the still-imprisoned Maxwell Lord, believing that he (having launched Bizarro against Supergirl in the previous episode) is behind this, but quickly realizes that she's wrong.
Meanwhile on the work front at Catco, Cat Grant, still furious that Kara broke things off with her son who then left National City just as he and his mother were reconnecting, is ready to fire her for not showing up. After Alex pleads the importance of the job to Henshaw, he uses his shape-shifting abilities to look like Kara and cover at work, which goes pretty disastrously (though it must be said that Melissa Benoist does a really funny job of embodying elements of Harewood's Henshaw in the way she carries herself and speaks).
Alex, who for some reason is in Kara's apartment looking at old photos, is suddenly met by Astra, who compassionately explains that Kara was attacked by a telepathic parasite, the only escape from which is for Kara to reject the fantasy. Off camera Astra provides her with information she needs, the idea being that they'll use a DEO virtual reality device to enter Kara's mind and convince her to "come back" (what kind of mumbo science allowing this isn't really offered up, though they use Lord to modify the device - which still doesn't provide much of an explanation).
Winn, who along with James is at the DEO, comes up with the suggestion that the fact that Earth's satellites have been knocked out by the solar storm could tie in to Non's plan - which Henshaw finds intriguing enough to invite him to temporarily work with his team (seriously?).
Utilizing the virtual reality device, Alex shows up on "Krypton" and is quickly restrained by guards and deemed an alien spy, sentenced to be exiled into the Phantom Zone. Alex fights against the guards, all the while pleading for Kara to remember her life on Earth as Supergirl and the people who love her. Ultimately it works, as Kara proclaims that as much as she wants to stay there with all of them, none of this is real and she has to go home. Both Alex and Kara awaken at the DEO, Kara completely stunned by the sense of loss she's suddenly feeling. That shock, however, quickly turns to fury when she is told that Non was behind the attack.
Winn has also discovered that Non is using Maxwell Lord's servers to further his ends, having left a mysterious virus of sorts behind. Shortly thereafter, Non is located and a battle ensues between he and Supergirl and she, driven by the emotional pain of what she's been through, absolutely kicks his ass! In the meantime, as Astra is threatening Alex (now they're enemies again, it seems), J'onn J'onzz shows up and engages her in battle. Astra gets the upper hand and is about to deliver a death blow, when Alex comes up from behind and, using a Kryptonite sword, plunges it through Astra's back and out her chest, resulting in her death shortly thereafter.
Non manages to escape, and Supergirl, hearing Alex call out to her, flies to her location, where she is told by Henshaw that he struck the blow against Astra. As Astra dies in her arms, she tells Supergirl she's happy that she came back from the Black Mercy and is given some solace in hearing that she was in Kara's fantasy not as an enemy, but as family. Her final words are that "Myriad" has begun.
At episode's end, Kara is reunited with James, Winn and Alex, and she explains that she chose to come back because she realized she belonged there, with her family. And in an oh-so-adorable fashion she smiles, "There's no place like home."
There are so many contrivances in this episode that it's maddening – Alex being in Kara's apartment when Astra shows up, Winn's computer prowess being such that he can find out things that Henhaw's entire team can't, the dopey virtual reality device allowing Alex to enter Kara's subconsciousness, the way that Winn can be at Catco one minute and back at the DEO the next, and Astra and Alex going from cooperation to a death battle among others. Also, Calista Flockhart's Cat Grant has got to get over her anger towards Kara soon; she's been bitchy from the start, but it's been an enjoyable bitchiness to watch with the knowledge that it was born out of her need to survive and claw her way to the top. This form of it, however, just comes across as mean.
What genuinely saves For The Girl Who Has Everythingis Melissa Benoist's performance. She brings equal doses of passion, empathy and vulnerability to the role of Supergirl. The fantasy she finds herself in feels like a natural extension of – and now a resolution to – what she's been dealing with through much of the season. This feeds into the moment when she removes herself from the Black Mercy; the shell-shocked expression on her face is so genuine. To see her fury unleashed against Non is cathartic not only for her, but the audience as well.
In many ways, this episode felt like a season finale. With another batch of episodes to go, it will be interesting to see in what direction the show will take Kara's emotional arc from here.