Manhunter

"Manhunter" is the seventeenth episode of the first season of Supergirl. It is set to air on March 21, 2016.

Synopsis
J’onn J’onzz reveals the details of meeting Kara and Alex’s father, Dr. Jeremiah Danvers, and assuming Hank Henshaw’s identity. Also, Kara debates trusting someone new with her secret identity and Siobhan plots against Kara.

Plot
Kara is out sick at CatCo but by now National City is starting to see her as unfavorable, and even Cat is starting to be concerned. As Winn is about fill in for Kara, he gets a message from Siobhan to meet him and leaves Kara's duties to James. At Noonan's, Siobhan tells Winn that she has been blacklisted and blames Kara, but Winn believes Siobhan will be back on her feet. Meanwhile at the DEO, Alex visits J’Onn, who refused Alex's help, but is then called to the main room, where Lucy Lane has shown up, and bought in Colonel Jim Harper. They been sent to find out who has been infiltrating the DEO and want to clean up the agency. The two take J'onn to a interrogation room that is so alien proof that Kara can't listen in.

Inside the room, J'onn tells the two about what happened ten years earlier in Peru, when he befriended Jeremiah Danvers, which began with the real Hank Henshaw leading a manhunt for a alien who he believed was dangerous. Jeremiah was against this and Hank did not want to hear it. During the mission, a snake attacks Jeremiah and he is saved by J'onn, and during the cold evening the two bonded and became friends as Jeremiah told him about Kara and Alex while J'onn explained about having a family until they were killed on his home planet of Mars, leaving him the sole survivor. Jeremiah promises to help him and inform the DEO that he wasn't a threat, but Hank appears and shoots J'onn. This lead to a fight between Jeremiah and Hank that resulted in Henshaw being thrown over a cliff after he stabs Danvers. Before he dies, Jeremiah asks J'onn to watch over his daughters. However, Jim, who was close friends with Hank, doesn't believe him. Jim tells Alex she is next.

Inbetween the events, Siobhan sneaks into Cat's office and leaves a e-mail that evening so she can set up Kara. Later on, Cat confronts Siobhan and tells her that Winn helped her figure out it was her who wrote the e-mail and not Kara. Cat tells Siobhan she will answer to the police if she ever comes back. That night on the balcony, a drunk Siobhan is furious at Winn for turning on her, even as he tells her that being a criminal and manipulating people isn’t a way to get what she wants. Suddenly, Siobhan loses her balance and stumbles off the roof. Unfortunately, her sonic scream somehow stops her from falling inches from the ground, thus the beginning of her persona as Silver Banshee.

Alex is grilled by Lucy and Jim. She explained how J'onn as Hank approached her to join the DEO after she was arrested and jailed, saying that she was special, and that she owed it to her father to be the person he knew she could be. Alex even passes her lie detector test, but Lucy doesn't believe her. After Kara discovers earphones so she can listen in, she is stunned that Lucy and Jim are taking the two to Project Cadmus.

When Kara tells James about what happened and about Project Cadmus, James tells her that the secreted location is a genetic engineering facility, and even Superman is against using the place, which is why he won't work with the government. This left Kara with no choice but to have James bring Lucy over to the apartment. When Lucy arrived, Kara reveals to her that she is Supergirl, but Lucy is still distrusting of aliens, believing they lie. This is when Kara explained to Lucy why she kept her powers a secret for which she had no choice, as she explained that in her past as a teen she heard a explosion from a burning car and springs into action, rescuing a woman and her baby before it blew up, injuring Alex, who chased after her. Afterwards, Jeremiah gives Kara a pair of glasses lined with a little lead to suppress her vision powers and tells her not to use her powers, lest she endanger people. Years later, Kara starts her job at CatCo, and convinces Cat Grant to hire her for the assistant's job, saying that she’s not special, she just wants to be useful and is willing to sacrifice everything, as Kara tells Lucy.

After a moment of clarity, Lucy agrees to help Kara. Later that night, as the vehicle is en route, they are surrounded by motorcycles that throw the truck off course. One of the cyclists is Supergirl, who disarms the guards, while the other cyclist, Lucy, help Alex and J'onn escape, but not before J'onn erases Harper's memory of having remembered meeting him, but discovers that Harper now remember that Danvers is alive at Cadmus. Alex tells Kara that she will go with J'onn to find Cadmus while she stays with Lucy to help take care of the guards. Later on at the DEO, Lucy, who now in charge, informs Kara that Harper has resigned. Upon being informed that a bank robbery has taken place, Lucy encourages Kara to earn back the public trust by stopping the criminal activity in progress.

Trivia

 * J'onn is shown to like Chocos (a trademark-friendly version of Oreos), which is taken from the comics.
 * Cat talks on the phone with a certain "Kate" who has an influential grandmother-in-law.