- "That creature and its kind slaughtered the Green Martians. The White Martians came from beneath the planet's surface, bringing fire from the planet's guts. And they burned us all."
- —J'onn J'onzz to Alex and Kara.
Kara must help Hank face his painful past when a White Martian, a member of the alien race that wiped out his people, kidnaps Senator Miranda Crane , an anti-alien politician. Also, Cat's estranged son, Adam, arrives in National City.
As Kara rescues a family from a forest fire, she reads a letter that she dictated about Cat's son, Adam. When she later meets up with Alex to talk about Winn, they run into guy who was asking about Cat, with Kara hoping that Cat will meet him soon. The two then see on the TV screen Senator Miranda Crane rallying around an anti-alien propaganda, which James has volunteered to cover despite Cat's dislike for Crane because of her views. Cat also is upset with Kara when she sees a person in her office and calls security; its her son Adam. She wants to have dinner with him but he turns her down. Cat then threatens Kara for interfering, but Kara, on the verge of being fired, turns things around by offering to have the two dine together by getting them reservations.
Outside near City Hall, Miranda's speech continues to draw crowds as Hank and Alex check the area for alien activity when a fast-moving white alien appears and attacks. Alex and Hank races to stop him but suddenly Hank's vision of what happened on Mars starts to come back and Alex saves him before he is run over. James immediately uses his watch and Kara as Supergirl appears, rescuing Miranda and against her wishes takes her to the DEO headquarters. Alex also questioned Hank about why he froze, and he explained to both Alex and Kara that he knows the attacker: it's a White Martian, part of a subterranean race that wiped out dozens of his people on Mars, including his entire family. Hank wants to handle the attacker personally, but fears that if he reveals himself to the world, General Lane will try to take over the DEO. However, Kara tells J'onn she will help him.
At CatCo, Kara helps Cat out with getting to know Adam while at dinner, which later on becomes awkward and as expected does not go well after Adam found out about the letter. James shows photos of the attack to Kara, who notices that some of them show Miranda's eyes glowing white—much like those of the White Martian. James remembers those pictures were taken after Kara supposedly rescued Miranda. Realizing what this means, Kara calls Alex at the DEO. Back at the DEO, "Miranda" plays mind games with Hank about an alien mole within the DEO and threatens to out the DEO if he doesn't conduct an investigation. When she suddenly mentions that she was attacked by a White Martian, Hank becomes suspicious.
Kara tells Alex that the White Martian is at the DEO, disguised as Miranda. Alex arrives with a gun pointed at "Miranda" just as Hank goes for his weapon, but the White Martian is too quick for them. She goes on a rampage through the building. J'onn suddenly starts having visions of White Martians taking a group of Green Martians. Just as Miranda is about to attack, Kara shows up to challenge her only to have the White Martian escape. Kara is then distracted by Cat and returns to CatCo, who is upset over the dinner earlier because of the letter, which prompts Kara to go see Adam personally. After a short talk and an admission from Kara about the letter, Adam agrees to meet with his mother on the condition that Kara joins them. During their dinner, Kara acts as a mediator and after tense talking both Cat and Adam start having a normal mother-son relationship.
Alex tells J'onn that she felt bad for encouraging him for using his powers and shouldn't be at fault, but J'onn tells Alex about how the White Martians killed his family, including his wife and daughters, K'hym and Tanya, before he escaped. He then examined a tissue that came from "Miranda" and over Alex's concerns tracks the impostor down by hovering above the city using telepathy, leading him to her lair located in a sewer. As Hank, he brought Alex and the DEO agents in to capture the White Martian, and stumble upon the real Miranda Crane and rescue her, except for Alex, who becomes bait after the fake Crane captures her.
J'onn then uses telepathy to negotiate with the White Martian while telling Kara to rescue Alex so he can kill her, which Kara objects to. The two arrive in the desert ready to come face to face with Miranda and pleads with her to let Alex go. J'onn is ready to surrender to the White Martian but Kara stops the alien and J'onn transforms into the Martian Manhunter and a battle ensues between all three. J'onn decides to take it further as he places Kryptonite cuffs on Kara so he can kill the White Martian, but Kara talks him out of it and he gives in. After they place the White Martian in the DEO cell, the alien vows there are millions like her ready to kill J'onn and won't rest until he's dead, but Kara tells her she's ready for them. The real Miranda later thanked Supergirl and is ready to change her mind about her feelings about aliens.
Later that evening Adam visits Cat to tell her he is staying in town, as it turns out he has a crush on Kara, and immediately asks her out on a date. This prompts Kara to ask Alex about dating tips but Alex tells Kara to have fun. Meanwhile, in another part of National City, a car is dangling along a bridge ready to fall, when a mysterious woman who looks like Supergirl flies in and picks up the vehicle, then drops it. The event is caught on television, where the Danvers sisters see it.
- The title references the tagline from the original Adventures of Superman TV series.
- J'onn J'onzz references two daughters, K'hym and Tanya. Tanya is not canonical to the comics, but K'hym J'onzz originally appeared in a 1988 publication.
|Supergirl season 1|
|"Pilot" • "Stronger Together" • "Fight or Flight" • "Livewire" • "How Does She Do It?" • "Red Faced" • "Human For a Day" • "Hostile Takeover" • "Blood Bonds" • "Childish Things" • "Strange Visitor From Another Planet" • "Bizarro" • "For the Girl Who Has Everything" • "Truth, Justice and the American Way" • "Solitude" • "Falling" • "Manhunter" • "Worlds Finest" • "Myriad" • "Better Angels"|