'Supergirl' Season Four Premiere Recap With Spoilers: "American Alien"

"American Alien" opens with a montage of Kara flying around the world, saving people from all kinds of situations — stopping a robber in Madrid and saving a train from crashing in Kaznia. She flies back to National City to attend a press conference being held by President Marsdin.

Alex is training new DEO recruits when Brainiac-5 enters to inform her that the President is at the agency. Marsdin walks in and informs Alex that she believes J'onn made the right choice in making her his successor.

At CatCo, James congratulates Kara on asking Marsdin the tough questions at the press conference and Kara reveals that James might be charged by the National City DA for revealing himself to be Guardian. Lena pulls James aside and expresses concern over his investigation — James reassures her that everything will be alright.

We see J'onn sitting in a circle at an alien support group.

Some time later, we see one of the aliens from the group walking at work when he's approached by two henchmen. One of the henchmen cut the tusks off the alien's arm so they can use it to access a secure facility on the lab they're in. The alien's able to call Supergirl but as soon as Kara arrives, she's quickly stopped by new-age technology the two henchmen brought with.

They get an alert at the DEO that Supergirl has crashed into a street any Brainiac-5 flies off to save her. After he unlocks the cuffs holding her down, Kara flies off to try and stop the attackers at the lab. They use a grenade to stop Kara again and they're able to escape.

J'onn arrives and Kara reveals to him that the attackers entered the lab to steal one of the facility's EMP weapons.

Back at the DEO, Alex confronts Brainy about flying off without backup earlier. Upset, Alex puts Brainy in his place and reminds him to respect her orders.

Kara's in the elevator when a nervous worker runs in and we find out it's Nia, a new reporter at the organization.

Briany calls Kara to tell her that the DEO has positive identification on the robbers — siblings Otis and Mercy Graves. Brainy informs Kara that he knows an associates of the Graves' — Lillian Luthor. Kara visits Lillian in prison, where her daughter Lena is currently visiting. There, Kara finds out that Mercy had previously been the head of security for Luthor Corp under both Lex and Lillian.

The alien support group is meeting up for another session when the bar they're in is attacked with explosives. Kara arrives to speak with J'onn and although the latter insists that the two attacks of the episode are connected, but Kara doesn't agree.

Alex and Kara get together for dinner and the latter notices her sister stress eating. Alex reveals that Brainy is stressing her out at work, to which Kara mentions that she's fighting with J'onn after their prior disagreements.

The Luthors are continuing their chess game in prison when Lillian questions her daughter about L-Corps' image inducer technology. Lillian notices Lena is bothered by something and Lena brings up James' investigation. Lena then mentions that she wants to work on all her previously failed relationships.

Brainy calls Kara with the location of the Graves' operation and Kara instantly flies out there. At the warehouse, Kara uncovers multiple computers with various chatrooms pulled up — each having various people talking about how they want to kill all aliens. She uncovers plans that the graves drew up about attacking President Marsdin's alien summit at Camp David.

Kara visits J'onn and tells him he was right about a large anti-alien movement building and informs him that there's an attack planned on the President. J'onn refuses to help out, taking a passive stance on the issue. Kara flies off to the White House to try and convince Marsdin to cancel the summit.

Not wanting to cave to fear, President Marsdin refuses to cancel the summit. Instead, she orders Kara to work with the DEO and Secret Service to ramp up security around Camp David during the summit.

Kara's hovering above Camp David when an EMP flies in and disables all of the electricity. From the DEO, Brainy's quickly able to restore electricity, but Kara notices two DEO agents knocked out in the woods. The Graves have entered. the facility disguised at DEO agents.

The Grabes try attacking the president, but Alex thwarts the attack. In a pursuite with the Graves, Kara's only able to stop Otis — who's quickly apprehended and taken to the DEO. While there, Alex notices Brainy wearing some of Winn's old clothes and when approached about it, the two begin to reconnect.

Using information she got from her mother, Lena offers evidence to the district attorney to put away one of her mother's money-laundering associates. In exchange for this new evidence, the DA agrees to stop any investigation into James' role as Guardian.

The district attorney hosts a press conference to announce that James won't be indicted for past events, but she warns that if he were to fight crime as Guardian in the future, he'd be charged with obstruction of justice.

Kara and J'onn grab a drink at the bar and forgive each other. They're talking when a news report comes across with footage of the assassination attempt on President Marsdin. The news footage reveals Marsdin's true identity as an alien.

The episode ends with Kasnians training Kara's doppelganger in a tunnel below ground.