A brother-sister team with ties to the Luthors attack an alien scientist, prompting John to suspect a new, anti-alien movement in National City. Kara helps a new cub reporter at Catco, and Lena worries about James' impending indictment for vigilantism.
As the country is rocked by a shocking revelation about the President, Mercy Graves targets the alien masking technology inside L-Corp. After Brainy and Nia feel the sting of anti-alien bias first-hand, Nia turns to James Olsen to intervene.
Ben Lockwood faces a rapidly-changing world when the government welcomes off-world aliens as American citizens, which he perceives to be a threat to his family and the family steel business -- slowly transforming from a mild-mannered professor into the villainous Agent Liberty.
J'onn teams up with a man named Manchester Black to search for Fiona, ending up on the trail of the anti-alien movement. Supergirl struggles with her new reality inside a protective suit, and Brainy struggles with his emotions.
As Alex prepares for Colonel Haley's new role at the D.E.O., Liberty recruits his own Parasite to use against National City's alien population. Kara writes a profile of a legendary alien healer, and is surprised by the negative backlash from the anti-alien community.
James tries to get loser to the Children of Liberty, while Manchester Black conducts an interrogation. Lena and Miss Tessmacher experiment to try and unlock the powers of the Harun-El, and Colonel Haley flexes her authority at the D.E.O.
James gets a face-to-face meeting with Agent Liberty, who intends to use James for propaganda. Meanwhile, Lena begins morally dubious human trials in what she hopes will give regular people super powers.
Manchester Black confronts Ben Lockwood in his home, placing Lockwood's wife in danger. When Nia has a powerful and distressing dream, Brainy and Kara help her to embrace her secret abilities to track down Agent Liberty.
After Dr. Deegan takes another shot at rewriting reality Oliver and Barry find themselves on the run from the law, with Kara locked up inside Star Labs -- and a dark Superman reigning supreme.
Colonel Haley sets her sights on learning Supergirl's secret identity, forcing Alex to run interference with her own agents. Meanwhile Supergirl searches for a shimmering alien after an attack at sea.
Kara joins Nia on a trip to her hometown, where a disturbing dream about her mother brings a bad omen -- and complicates Nia's relationship with her sister. Alex chases a street drug that is turning users into raging monsters, and James faces a difficult choice when a reporter brings him a story about Lena's company.
With his P.I. shingle newly hung outside his office, J'onn welcomes new clients. Trying to take her mind off what happened at the DEO, Kara decides to team up with J'onn on his latest assignment, which unfortunately ends up tying directly into Alex's current investigation that involves the villain Menagerie. (The CW)
Manchester Black assembles a team of super-powered criminals to go after anti-alien forces, prompting Supergirl to call on her own super-friends to stop him. While Nia trains with Brainy at the Fortress of Solitude, Lockwood learns that he may be losing the people's confidence.
While J'onn and Supergirl track Manchester and his Elite, Alex is assigned to provide protective detail for Ben Lockwood -- who takes advantage of his new position to press for an end to amnesty for aliens.
After James is shot Lena turns to her brother, the ailing criminal mastermind Lex Luthor, for help in completing her research -- which may be the only way to save both men. Meanwhile Kara joins J'onn on his hunt for Manchester.
Lex Luthor's recent past is revealed, leading him from his criminal conviction to an expanding empire run from prison -- and a meeting with Kara's Kaznian doppelganger, who is in need of training.
Supergirl, Lena, and Alex go on the hunt for Eve Tessmacher, whose true loyalties have been exposed. While James recovers from a trauma, J'onn seeks to commune with his father's spirit to rediscover who he is supposed to be.
The President declares marshal law after Supergirl's double impersonates her in a brutal attack on Washington. While Kara and Lena search Stryker's Island for clues to Lex's whereabouts, Alex must defend the city's aliens from Ben Lockwood's newfound power trip.
With Supergirl lying low Dreamer steps up to protect innocent aliens from Lockwood's forces. Elsewhere Brainy helps James to confront his deepest trauma, and Kara works to uncover Lex's secret dealings to try and clear Supergirl's name.
Kara and Lena fly to Kaznia to hunt down Lex, where they find Eve Tessmacher running interference for him. Alex gets a personal surprise and turns to Kelly for support, and a furious Lockwood goes on a rampage at the D.E.O.
Kara finds herself face-to-face with Red Daughter, as her plans to expose Lex are dealt a major set-back. Lena recruits her mother for help in de-powering Lockwood, and Alex struggles to recover parts of her lost memory. Meanwhile Nia, Brainy, and J'onn track a group of aliens who have been taken into custody.
Lex Luthor's schemes place him in the Oval Office, welcomed as a hero by the country. J'onn and Dreamer must help a group of alien prisoners escape from Lex's facility on Shelly Island -- before he can unleash his endgame on the Kryptonian colony of Argo.
