The episode opens up with firefighters struggling to contain a blaze. One of them says he hopes she shows up soon. He looks to the sky and is relieved to see both Supergirl and Superman flying towards the fire. They work together well, Superman containing the smoke while Supergirl puts out the fire. Immediately, they hear and alarm, and next stop two robbers from making their getaway. Both of them are enjoying getting to save the day together. Next, Hank contacts them about an alien threat.
At the DEO, both Winn and Alex call Hank out on being a grouch in regards to Superman. At Cadmus, Corben wakes up. He’s amazingly strong. The same woman is with him. She tells Corben that she is a doctor and encourages him to use his new powers against Supergirl and Superman. A male assistant in the room does not think Corben is ready, but the Doctor doesn’t agree, and calls Supergirl and Superman a menace. Corben glows green.
Alex is leading a team out of the DEO to deal with the alien that Hank mentioned earlier, since they have not heard from Supergirl. Before they can leave, Supergirl and Superman fly in, having dropped the alien in containment. Hank scolds Supergirl for failing to communicate that the threat was neutralized. Just then the power goes out. Winn says there is another power drain.
They go to the source of the power drains, the man from the pod, who is still unconscious. The power returns quickly as they discuss the stranger’s healing ability. Superman is furious that Hank is using kryptonite as a precaution against the strange man and leaves. Supergirl reminds Hank to be nice to her cousin, and Hank promises to get along with Superman. Alex asks Kara about their sister night plans. And Kara admits to inviting Clark to join them. At CatCo, Kara babbles to Clark, nervous about her first day as a reporter. Cat calls Kara into her office, flirting a bit with Clark as she does.
In Cat’s office, Kara is introduced to her new boss, Snapper Carr, the head of the investigation team. Carr does not seem especially excited or impressed with Kara.
Alex and Kara are setting up sister night in Kara’s apartment when Clark arrives. He immediately asks Alex for privacy, so he can tell Kara that it’s time for him to go home to Metropolis. Kara’s sad about him leaving, but they are distracted by the news showing a man about to jump off a bridge. They decide to save him, one last adventure.
When they get to the bridge, they learn the jumper is actually Corben. He gives Superman a blast from the green kryptonite embedded in his chest and calls himself Metallo. Metallo attacks Superman again, and Supergirl hurries to save her cousin. But Metallo barely registers when she hits him, and he is able to violently throw her before going after Superman again. Supergirl fights him, burning to skin from his hand to reveal that he is now a cyborg. Metallo finally blasts Supergirl with the kryptonite as well, before a now recovered Superman shoves Metallo far into the distance. Superman lifts Supergirl in his arms.
By the time they reach the DEO, Supergirl is able to walk with support, but is still dizzy. Superman angrily rips into Hank, reminding him that all the kryptonite was supposed to be safe at the DEO. Hank and Alex admit some was stolen four months earlier during a shipment. They had assumed one of the transporters took it, but they were all clean. Superman realizes there is a mole in the DEO who stole the kryptonite. Hank defends himself, pointing out how they needed the kryptonite to stop Non and Astra.
Suddenly all the screens in the city are taken over. An animated head talks about the alien “gods” who have stolen the planet. It names Cadmus as a group of scientists dedicated to stopping Supergirl and Superman. And anyone who sides with them.
Alex is worried about her father now that Cadmus has declared war on them. Hank sends Winn to use Non and Astra’s technology to make something Supergirl and Superman can wear to protect them from Metallo’s kryptonite. Superman and Hank agree to work together and head to the Fortress of Solitude to analyze leftover residue on Superman’s hand to see what the cyborg Metallo is made of.
Kara shows up at work, having missed a meeting. Snapper is not amused and informs Kara that she does not work for him, because she has not earned the right to be a reporter, no matter what Cat Grant says.
Kara finds Cat and asks her to talk to Snapper, but Cat refuses, telling Kara to stand up for herself. She can’t keep depending on Cat to fight her battles, because Cat won’t be there much longer. Kara assumes Cat is dying and grows upset, but Cat explains she feel stuck, like a shark swimming in circles, and is simply taking a leave of absence from CatCo to find something new. To dive. Kara doesn’t feel good about even more change in her life. Cat is touched. The two women hug and Cat encourages Kara to show Snapper how worthy she is. Metallo has returned to Cadmus. The Doctor is pleased that Metallo succeeded in harming Superman, a nearly impossible task. Her assistant is again doubtful. The Doctor decides it is time for Phase 2, and two goons grab her assistant, dragging him off.
Superman and J’onn J’onzz fly to the Fortress of Solitude. Once they arrive, J’onn turns back into Hank. Hank speaks Kyriptonian to Superman, comforting words about his loss. He points out their similarities, orphans from destroyed planets who lost everyone they loved. Hanks holds onto the kryptonite because he’s afraid of getting caught unprepared to protect the earth. Superman understands and does not hate Hank, but does not trust him either. What if the President ordered him to use the kryptonite against Kara? Kelex appears and scans Superman’s hand, identifying the metal as Promethium.
Kara walks to her apartment when she is joined by Alex. Kara talks about her problems at work and the feud between Hank and Clark. Alex offers ice-cream, and Kara admits she is thinking about moving to Metropolis with Clark. She gives a bunch of lame excuses, but Alex isn’t fooled. She loses her temper and accuses Kara of ignoring her since Clark arrived. They argue about how much Alex sacrificed to take care of Kara, only for Kara to talk about leaving. Kara admits to feeling alone without Clark. Alex reminds Kara that Clark abandoned Kara with the Danvers.
At the DEO, Winn searches for Promethium in the city. He finds Metallo, but admits that the new suits for Supergirl and Superman aren’t ready yet.
Supergirl and Superman find Metallo, who informs them that he is just a distraction from what is happening in Metropolis.
The assistant from Cadmus has been given the same powers, and as Metallo 2 he wreaks havoc on Krypton Park in Metropolis.
Superman flies to save his city. Metallo orders Supergirl to go with him, or else he’ll burn her. She promises that it isn’t over before following Superman.
Supergirl and Superman arrive too late. They look over the chaos and debris, and Superman blames himself for not being there.
Winn asks Alex for a screwdriver while he works, and she slams it hard into his hand. He asks why she is so grumpy, and she talks about how she keeps sacrificing for Kara. She hasn’t even had a date in two years. Winn talks about being raised in foster care after his father’s arrest. He was constantly told he was lucky, but that is not family. Family is showing up. Winn continues working, complaining that the trace amounts of kryptonite that remain in the air, like radiation, are making his work harder. Alex realizes they can use the trace kryptonite to find the mole.
Alex and Winn take a Geiger counter to the locker room at the DEO and search for a locker with higher amounts of kryptonite. They discover that the mole is an agent named McGill.
Alex finds Agent McGill and gives him the job of arranging transport of some kryptonite to Nevada on behalf of the President.
Supergirl looks for Alex at the DEO. Winn tries to cover, but Supergirl immediately catches on and demands to know where Alex is.
Alex catches McGill in the act of bringing the kryptonite to a warehouse. But she is attacked by several members of Cadmus, including the Doctor. Alex asks about her father, and the Doctor implies that he has been experimented on. The Doctor accuses Alex of being abused and brainwashed into believing the Kryptonians are good. She attempts to recruit Alex, but it doesn’t work.
The thugs grab at Alex, who successfully fights them, grabs her gun, and runs through the warehouse. They follow and shoot at Alex, but Supergirl arrives in time to save her. Once the fight is won, Supergirl apologizes and says Alex is the only reason she’s ever felt at home on earth. She also starts to come up with a plan.
At the DEO, Supergirl shares her plan with Superman and Hank. Catmus thinks they’re divided and divided they’ll fall.
Supergirl meets up with Metallo in National City while Superman finds Metallo 2 in Metropolis. They’re both wearing chest plates that Winn made, which succeed at stopping the blasts of kryptonite sent at them by both Metallos. Both sets of Supers and Metallos fight, and eventually both chest plates are broken.
Superman and Metallo 2 are watched by a little girl, who turns out to be J’onn J’onzz, who jumps into the fight to help Superman. Meanwhile, Alex wears her powersuit and joins Supergirl’s fight. Eventually J’onn rips out Metallo 2’s kryptonite core and Alex stabs the kryptonite inside Metallo with a pipe. Supergirl leans over Metallo, assuming Cadmus is watching through the cyborg. She threatens Cadmus, which the Doctor sees.
Cat stands on the balcony at CatCo. Supergirl joins her and asks Cat if she’ll miss it. Cat admits that she will. Supergirl admires her bravery, and Cat says she’s thrilled that she does not know what she is doing tomorrow. Cat tells Supergirl to be safe, and Supergirl asks Cat to come back some day. Everyone needs friends. Cat promises she will.
Supergirl changes into Kara inside CatCo, and sees James carrying a box of his things. She’s worried he is leaving because of her, but in fact Cat asked him to take over while she is gone, he is simply moving into Cat’s office. He offers to talk to Snapper about Kara, but she wants to handle it herself.
Kara delivers an article on the duel Metallo fights to Snapper, listing her research and effort. He tries to ignore her, but she insists that he read it. He skims the article and still tries to dismiss her. Kara calmly says she’ll bring the article elsewhere, and Snapper reluctantly accepts her, even though he does not like her. Kara is satisfied.0comments
At the DEO, Hank has all the remaining kryptonite in lead and gives it to Superman to get rid of. Superman says his goodbyes to Winn, Alex, and Kara. Then he flies away with the kryptonite.
Back in Metropolis, Clark immediately texts Kara and says he missed her. She texts him back, then Clark receives a phone call from Perry White. Supergirl sits by the still unconscious man from the pod. She promises that she will be there for him, he does not have to feel alone on earth. Suddenly, he wakes up and grabs her by the throat.