Supergirl Recap with Spoilers - Homecoming

The episode opens with Mon-El waking up in Kara's bed, but Kara's already gone. Mon-El wonders whether he was that bad....or that good. When he walks out into the living room, Kara flies in with flowers and coffee. After changing into regular clothes, Kara kisses Mon-El and admits it's nice to be able to kiss someone without breaking their nose. Mon-El wants to just spend the day in the apartment, but Kara says they need to be in the DEO in 20 minutes. She also asks Mon-El to keep quiet about their relationship, because she doesn't want everyone to comment on it.

Mon-El agrees, but immediately spills the beans at the DEO. J'onn says they need to inform HR (that's right, the DEO has an HR department), when an alarm goes off, informing Winn of Cadmus activity.

Supergirl and J'onn fly to intercept a Cadmus cargo convoy, protecting what they thought was a weapon shipment. When Supergirl intercepts the truck, she finds Jeremiah Danvers chained inside.

Supergirl and J'onn bring Jonathan back to the DEO, where he receives a hug from Alex and a warm applause from the other staff. He tells them that Cadmus kept him alive to turn Hank Henshaw into Cyborg Superman, and then kept him around to build other weapons. Mon-El walks in and points out (in his typical tactless fashion) that Cadmus seemed very sloppy about transporting Jeremiah, but Jeremiah deflects by saying the Cadmus has a new nuclear weapon that they plan on detonating and blaming on aliens. The nuclear energy came courtesy of Kara's heat vision from when Cadmus took Supergirl prisoner.

Jeremiah suggests that Winn track the bomb using Kara's energy signature and then reunites with Eliza. Mon-El pulls Supergirl aside and says that everything seems a bit too convenient. After all, it didn't seem like Cadmus was collecting Supergirl's energy and Jeremiah was in the belly of a beast for years. Mon-El reluctantly backs off after Kara invites him to a family dinner.

That evening, Jeremiah gets introduced to Maggie and tries to bond with his wife. Eliza says that they can't make up for lost time, but they can build something new instead. The extended Danvers family (plus J'onn) toast to Jeremiah's return. Jeremiah then asks J'onn to return to the DEO, which J'onn accepts. Mon-El gets suspicious how easy Jeremiah regained access to the DEO, but Kara quickly kicks him out of the apartment. Jeremiah leads Mon-El out and then says he knows who he really is and that Kara probably wouldn't like it.

Mon-El meets with Winn at the perennially unnamed alien bar and tells him of his concerns about Jeremiah. Winn thinks Mon-El is paranoid, but when Mon-El points out how Jeremiah just fell into the DEO's lap, he agrees to help. Winn just wants one thing in return: that Mon-El treats Kara right.

The next morning, J'onn gives Jeremiah the tour of the DEO and assigns Jeremiah to man the medbay. When J'onn leaves, Jeremiah quickly tries to access the DEO's mainframe, but Winn sees him. Winn points this out to Mon-El and Kara, but when confronted Jeremiah claims that he was just checking out old casefiles to see what his daughters were doing. Alex leads Jeremiah away, but not before yelling at Kara.

Kara tries to apologize to Alex and says that she's just being cautious. Alex won't listen to her and says that either Kara's a part of the family or she isn't.

Mon-El goes back to the alien bar and asks Winn for advice on how to be a better boyfriend. Winn tells him to stop trying so hard and stop trying to protect Kara. Afterwards, Winn gets an alert saying they've found Cadmus's fusion bomb.

Alex, Supergirl, Mon-El and a DEO strike team head in to intercept bomb, but they don't find anything there. J'onn realizes something's wrong, especially after Jeremiah walks out of the DEO control room. J'onn discovers that he can't read Jeremiah's mind and that Jeremiah has a cyborg arm. Jeremiah quickly overpowers J'onn, attacks Winn and downloads the DEO mainframe onto a portable device. He then grabs a gun and flees the DEO.

Supergirl, Alex, and Mon-El return to the DEO and find out that he's turned. Winn says that he planted a tracker on Jeremiah to follow him.

Supergirl and Alex find Jeremiah meeting with Henshaw and Lillian Luthor's mom. Henshaw blows up a nearby train bridge to draw Supergirl away, while Alex goes after Jeremiah and the others. Alex catches up to Jeremiah and pulls a gun on him, but she refuses to kill him. Jeremiah runs away, but not without at least a little regret.

When they return to the DEO, Alex explains to her mother what happened. Alex then goes back to her apartment and drinks herself into a stupor. Maggie stops by and Alex immediately breaks down. Meanwhile, Mon-El checks up on Kara at her apartment. Instead of talking, Mon-El asks Kara what she needs but Kara just wants him to be there with her. Winn calls and says that Jeremiah stole the National Alien Registry, meaning that Cadmus now has info on all the aliens.

Back at Cadmus, Lillian says that she has a deal with Jeremiah and then shows him a giant spaceship.