Supergirl #1 (2017)

Batman and Superman look on while Supergirl rescues Air Force One, as the Calculator also looks on. Supergirl zooms away, losing Superman, then notices the Calculator's satellite, and confronts Batman. She meets up with "Batgirl," fights Poison Ivy and Harley Quinn, and proves invulnerable to synthetic kryptonite. Batgirl is revealed to be Clayface, and Supergirl defeats him. It turns out that Lex Luthor is behind the Calculator's monitoring of Supergirl and been testing her.

Jeff gets caught in Zatanna's trance, and gets sent back to King Arthur's Court.

Supergirl reviews her origin, then meets up with Stargirl, who is watching the Justice Society of America battle Solomon Grundy. Power Girl shows up to help, and Supergirl intervenes to help her, dispatching Grundy. When they shake hands, Power Girl goes crazy and attacks Supergirl. Green Lantern intervenes in the fight, and isolates them. Apparently "allergic" to Supergirl, Power Girl meets her later, but refuses to be her friend for now. Desiring some peer support, Supergirl goes to seek Superboy at the Kent farm, but he confronts her instead.

Supergirl and Superboy fight in the sky over the Kent farm, but stop after Supergirl dislocates his jaw (and then fixes it). Cyborg and Beast Boy appear and attack Superboy, while Wonder Girl and Raven confront Supergirl. Supergirl defeats Wonder Girl, and is enveloped by Raven, who can't hold her. Finally Supergirl offers to just leave, but Superboy says "my cousin doesn't have to leave, you all do." Robin, Kid Flash, and Starfire appear, and then a jump to Luthor becoming familiar with his Kryptonite gauntlet.

Supergirl and the Outsiders spar at their headquarters, when Nightwing intervenes. Supergirl impulsively kisses Nightwing, and then rushes off to find Luthor, sabotaging the Outsider's jet so that they can't follow. Starfire follows anyhow, but is zapped by Luthor, wearing his armor. He proceeds to use a variety of Kryptonite rays on Supergirl, ultimately using a black kryptonite ray. That releases a Kryptonian-spouting dark Supergirl, who warns Luthor that he’s just made the biggest mistake of what's left of his life.

Dark Supergirl confronts Luthor. They fight, and Luthor flees after she destroys his glove. She flings him into the Watchtower on the moon, where he is confronted by Green Lantern. Dark Supergirl catches up, takes Green Lantern’s ring, and uses it to knock him out. Meanwhile, Starfire awakens Supergirl, and she seeks out Dark Supergirl. Back in the Watchtower, Luthor uses the JLA transporter to go back to Earth, as Hawkman tries to stop him. After defeating Hawkman, Black Canary, Flash, and Martian Manhunter, Dark Supergirl is confronted by Supergirl.

Dark Supergirl recalls just before Kara left Krypton, her father told her she is to kill the baby Kal-El. She is then "made innocent" to assimilate better, but her "true" self emerged under Darkseid. Supergirl claims Dark Supergirl is lying and they fight. The JLA confronts them, and they wrestle some more. After more fighting, Batman, Superman and Wonder Woman show up. Supergirl asks that both of the Supergirls be bound by Wonder Woman's lasso, and is asked "Who is Kara Zor-El?" After an explosion, both are merged again, into "Supergirl," who wishes to be known as that and not Kara Zor-El.

Supergirl is in Kandor as someone calling himself Kal-El is railing against unbelievers, heretics, Nightwing and Flamebird. She is assaulted by aliens as a Kryptonian in the wrong sector. Nightwing arrives to stop them, but Supergirl injures an alien and kills them. Nightwing intervenes and Supergirl tells her she thinks the key to returning to Argo City is here. "Kal-El" is telling his slaves they can only be redeemed by serving Kryptonians, when cries of "Lies" are heard. Nightwing and Flamebird attack and free the slaves, as "Kal-El" arrives and destroys all witnesses to the attack.

"Kal-El" recognizes Flamebird's tattoo and tracks down who was tattooed. Monitors interrupt Nightwing and Flamebird's meeting with the rebel leader and "Kal-El" threatens to kill people until the pair surrenders. He starts, but "Nightwing" and "Flamebird" rescue a mother and child. The child is a bomb that explodes, injuring the pair. The real Nightwing and Flamebird arrive and Flamebird starts beating "Kal-El", as instructed by a flashback of her father. Nightwing is unable to stop her. Flamebird hears a voice from from "Kal-El's" mother, Saturn Queen, telling her to unmask and kiss "Kal-El".

Kara is to wed "Kal-El" under Saturn Queen’s mind control. In a flashback, Kara sees Saturn Queen defeated by a Superman/Batman team, finding Ultraman in the Phantom Zone, and landing together in Kandor. Another flashback breaks Saturn Queen's control and Kara attacks her and Ultraman. Saturn Queen orders Power Girl’s immediate execution, but Kara intervenes and frees her. As Kara is about to kill Ultraman, Saturn Queen mentally intervenes, asking that he be spared if she shares information about Argo City. The information is shared, Kara leaves Ultraman alone, and departs with Power Girl.

While talking to Boomer, Supergirl flashes back to her recent dispute with Power Girl, visiting Wonder Girl in Themyscira, talking with the Kents, and a fight between her parents on Krypton. She needs money, so she sells a Kryptonian "Sourcedoc" medical device to Batman for one million USD, so she'll never have to worry about money. He tells her that Superman is worried about her. After dinner with Boomer, she saves a girl from a truck and the girl tells Supergirl her new costume is too dark. She returns home, where Wonder Girl appears after a blowout with her mom, and they comfort each other.

Supergirl is now Claire Connors, new at Guggenheim High School. A geek group invites her to sit with them at lunch. She flashes back to harassment on Krypton as part of the El family. Later, she asks advice from Wonder Girl while fighting Monsieur Mallah. Becky hears Drew asking Supergirl out and invites her to a sleepover. Supergirl invites Sarah but the girls embarrass Sarah. Next day, Becky apologizes but posts things on the internet. Sarah pranks Supergirl and Becky tells her to stay away from her boy Drew. After confrontation with a "cool kid," she takes off her wig and flies away.

Kara attends a rave with a superhero theme and enjoys herself. Suddenly, the wall blows in, as a result of a fight between Terra and an Empathosaur. She reluctantly joins the fight, but the creature senses her emotions, and causes her to flee temporarily. But she returns and fights, even when the creature confronts her with images of her father. Together with Terra, they defeat the creature, returning it to the earth. Supergirl is somewhat intimidated by Terra, who seems to have her act together. Later, she discusses this all with Boomer, who invites her out for a night on the town.