Kara gets a taste of what life would have been like if she remained on Krypton while Hank gets to fee the wrath of Cat when he covers for Kara while under the influence of the alien parasite.
The episode opens with Kara waking up in her bedroom on Krpyto. Calex, her medical droid, tells her that she has awoken after suffering Argo fever. Kara knows something isn’t right when she sees an outfit that belonged to her her mother and this is when Alura appears.
Even after seeing her mother again, who tries to convince her that she really is on Krypton, Kara is still not convinced but starts to slowly come around to the idea when she spies a gift she made her father and more so when she sees him, her aunt Astra and a tween Kal-El asking for her help to open up a holo sphere that shows Krypton from space.
Meanwhile, back in National City, Cat asks Winn where Kara is as she isn’t reachable via cell phone. Winn says the reason why is because of all the solar flares happening that is affecting cell signals. However, Winn and James know something is up with Kara and asks Alex to check in on Kara with them.
When the three break into Kara’s apartment, the find her unconscious with an alien parasite latched on. The thing is Kara’s brain activity is normal but is still out cold. Alex immediately blames Lord for Kara predicament but Hank says Lord knows nothing.
Alex and Hank try to use a claw to forcibly remove the alien parasite but it causes Kara’s vitals to flatline.
So Alex goes to ask the Alura AI to see what has attacked Kara but alas the AI doesn’t have enough information to help. Alex emotionally pleads with the AI about how much Kara means to her and how early on it was not always the case. But the AI reiterates that she doesn’t have sufficient information to help.
Back at CatCo, Cat pretty much tells Winn that if Kara doesn’t show up in the next hour she is fired. So Hank, hilariously, becomes Kara for a day. While James and Winn tells this elite agent of the DEO about Cat, Hank says he can handle her. However, we see Hank unable to handle the firecracker that is Cat and actually looks intimated by her. Later on, Hank tries to make amends for Kara’s sake but alas it doesn’t work. So Hank puts on the water works to apologize to Cat for hurting her and Adam and tries to get a day off. Cat, is not impressed but grants “Kara” the day off if only so she won’t see her face again for the rest of the day.
The people behind Kara’s predicament is Non, who is using the solar flares to distract people from their real mission and the Black Mercy to get Kara out of the picture. Astra learns what Non has done to Kara and covers her displeasure by still pledging her loyalty to their cause. Their mission by the way is called Myriad and apparently is meant to finish what they started on Krypton here on Earth.
Alex is at Kara taking a look at a picture of her and Kara. Astra arrives and tells Alex about the Black Mercy and each passing moment Kara spends in its world, the more real it will become for her. Astra proposes a solution to Alex.
Back at the DEO, Alex tells Hank about hooking up her consciousness to Kara’s to try and convince her that whatever world she is in, isn’t real. Kara is the only person that can pull herself out.
Winn and James are brought back to the DEO to be there for Kara when she wakes up. Alex tells Hank some bad news that it could take days for DEO techs to figure out how to merge her consciousness.
But this is where Lord is brought in as he figures out a way for the consciousnesses to merge. Before going under, Alex gets James to promise to stop Hank from prematurely pulling her out.
Alex finds herself on Krypton and stumbles upon Kara talking with her parents about a boy that she likes. Kal-El is there enjoying family time too. Alex bursts in and Kara has no clue who she is and shields Kal-El from her. Alex is knocked out and her vitals start to spike. James spots Hank from pulling her saying Alex wanted him to. Hank only cares about saving both Kara and Alex.
When Alex wakes up, we see Alura sentence her to the Phantom Zone. Alex starts pleading for Kara to remember her life on Earth (we see Kara throughout the episode starting to not remember Earth) and her friends Winn and James and her. Alex manages to get through to Kara who tells her parents that she knows that this life isn’t real and tells her mom Krypton will always be in her heart and bids her goodbye again. Alura hugs Kara and tells her they will never let her go as her eyes go black. Throughout the scene, tremors are shaking the room and Kara is about grasp Alex when she disappears.
Alex thinks she was pulled out but it was Kara rejecting the fantasy and she wakes up. And boy does Kara look pissed especially when she finds out that Non was behind everything.
Meanwhile, thanks to Winn, the DEO figure out that the Kryptonians where using the solar flare as a distraction to hide the fact they are targeting six Lord Technology server farms. DEO does a divide and conquer approach but Supergirl wants Non.
Supergirl arrives and starts to beat the crap out of Non for putting her through the Black Mercy and having to say good bye to her family all over again. This fight is intercut with Alex’s fight with Astra. The Martian Manhunter joins the fray and just when it looked like Astra is going to kill J’onn, Alex impales Astra with a kryptonite sword. But before Astra does manage to accomplish her mission. Supergirl’s fight with Non ends when she has to stop a satellite from falling. Alex calls Supergirl to come to her location as Astra has been mortally wounded and to say goodbye. Hank tells Supergirl that he is the one to deliver the fatal blow. Kara and Astra share a emotional goodbye. Astra does tell Kara that it is too late to stop what Non has started. Hank, Kara and Alex have to go when Kryptonians start to arrive.
Back at the DEO, Hank tells Alex he took the blame because Kara sees her sister as a hero and doesn’t want to hurt that relationship. We then see Non with Astra’s body.
At Kara’s apartment, she explains to Alex, Winn and James why she imagined Krypton instead of Earth as he dream world. Kara’s friend and family understand and she realizes that there is no place like home. Winn is impressed at Kara for quoting a movie and the two have repaired their friendship. As the quartet make their way to enjoy Chinese food and ice cream, it looks like Alex is going to tell Kara that she was the one that killed Astra but instead shares how Hank tried to be her in front of Cat. Kara seems to think that idea funny and horrifying at the same time.
There is no new Supergirl next week as it is Grammy Awards so see you in two weeks.