Last week on Supergirl, she was poised to fight Alex to the death. This week we find out which of the sisters survive and whether Myriad can be stopped.
Alex fights dirty with blades made of Kryptonite. It’s also built into her suit, making it impossible for Kara to put her hands on her. Kara tells her she doesn’t want to do this. Alex tries to stab her and throws her across the alley.
Just as she’s about to kill Supergirl, their mother shows up and talks Alex down. She tells her how strong she is and reminds her of their family bonds. She prompts her to remember Jeremiah’s love. Alex snaps out of it. She throws the blades away and cries, apologizing.
Our heroes meet Max and Cat back at Cat’s old news station. Max says there’s evidence that Myriad works in the same part of the brain as hope. If they can give a hopeful message to all of National City, it should break the signal. Alex says hope for her father tossed a switch in her brain. Suddenly, she could feel again.
Max works to broadcast the signal to all televisions, computers and smartphones. Supergirl gives a heartfelt speech about working together. First Winn wakes up, then James, then members of the DEO. Slowly, the whole city awakens.
Non tells Indigo that Myriad has failed. Indigo says he’s dreaming too small and convinces him to kill the humans. They’ll leave Kara to rule a dead Earth.
At work the next day, James and Winn apologize to Kara for things they said under Myriad. They also thank her for saving them. James asks to talk about what happened before Myriad. Winn leaves them to it.
Kara asks James how he felt about the kiss, but Cat tells them they’re late for the morning meeting. They agree to talk later.
J’onn is in the custody of the DEO. General Lane tells his soldier to cuff him. Lucy yells at her father because J’onn just helped save the city.
Professor Danvers asks Alex what she didn’t tell her when she visited. Alex tells her that Jeremiah is still alive and that she’s going to get him back.
Max tells the DEO that the Myriad signal is increasing exponentially. Indigo and Non are trying to literally blow everyone’s minds. They have four hours. Max tells Supergirl she needs backup. He’s afraid she’ll die. She asks him not to tell Alex her odds.
Kara goes back to work. She thanks Winn for his friendship and breaks things off with James, saying he deserves happiness. She even tells Cat that working for her is an honor because of her strength and grace.
J’onn talks to Supergirl about giving up. She says she’s not giving up, but if she dies during this mission, she’s at peace with it. She kisses him on the forehead.
Max finds that the Myriad wave is being powered by a ball from Krypton that used to power whole cities. The wave is coming from Nevada. General Lane says it’s Fort Roz. They left it where it landed and labeled the area a nuclear testing zone.
J’onn offers to help Kara take down Indigo and Non. Lucy orders him released. Alex tells them both to be careful. In a heartbreaking moment, Kara gives Alex Alura’s necklace to hold onto.
Kara asks Non where his army is. He says they’re in their sleeping pods ready for takeoff. He tosses her the power ball, but he says the real power comes from the Fort Roz structure. Kara asks him to stop because Astra wouldn’t want this. He says the humans’ extinction will save the planet.
The countdown is at six minutes. Supergirl fights Non, while J’onn fights Indigo. All the humans have unbearable, screeching headaches. Indigo stabs J’onn in the gut and thinks she’s going in for the kill. Supergirl and Non lock heat ray vision. Indigo gets distracted and J’onn tears her body in half. Kara presses forward and blows out Non’s eyes.
Kara runs to J’onn and tells him they’ll shut down Myriad. Before she dies, Indigo tells them she locked the system. They won’t be able to fly Fort Roz away to save their friends.
With three minutes left in a pulse-pounding countdown, Kara calls Alex and tells her she has to fly the ship off the planet. Alex says she wouldn’t be able to get back and begs her not to go. Kara asks Alex to tell Jeremiah and their mother that they gave her a great life. She makes Alex promise to live a full life.
Kara strains to lift Fort Roz. She rises above the Earth’s atmosphere and throws it into space. She becomes stuck and loses consciousness. Alex arrives in her sister’s pod and pulls her back to Earth.
Alex gives Kara back her necklace. Kara gets standing applause from everyone at the DEO. General Lane thanks Supergirl and J’onn. The President has reinstated J’onn as the head of the DEO. He promises to work together with no more secrets.
Max and General Lane examine the power ball.
Kara gets an instant message from Clark saying that he’s feeling better and thanking her for saving the world. Cat arrives and throws Kara’s belongings into a box. Kara tries to explain whatever she did so she won’t get fired. Instead, Cat delivers her and the box to her new office. She’s being promoted. She’s to think about what she wants to do. Cat calls her by the correct name for the first time.
The Danvers family has dinner with J’onn, James and Winn. James gives Kara a photo of her that he loves, then surprises her with a kiss.
Something streams past the window, entering the planet’s atmosphere in a hurry. Kara flies off and finds a pod from Krypton. She opens it, stunned to see whoever it is.
See the season finale promo: