Arrowverse Wiki
Arrowverse Wiki
"This world is a crazy place right now. People acting, reacting. Escalating behaviors. Like what Morgan Edge did to Lena. What our lawmakers are doing. Sniping at each other, going round and round in circles, not doing any good. Reminds me of Mars before the civil war. But like my father said then, 'There is great power in being the calm in the center of the storm. A beacon, to show the way.' Supergirl is here to remind us on Earth about what's best in ourselves. That's what's most important. It's more important than if you were to ever catch another bullet."
J'onn J'onzz to Kara Danvers

"For Good" is the twelfth episode of the third season of Supergirl, and the fifty-fourth episode overall. It aired on January 29, 2018.




Guest starring[]



"For Good" begins with Kara awakening from a bad dream. She sees Reign and the Worldkiller we saw toward the end of a last week's scene. At the DEO, Kara tells Winn and J'onn about the vision in her nightmare.

Mon-El strolls in to advise them that while Worldkillers were made on Krypton, the Worldkillers may have been hereditarily adjusted to be impervious to kryptonite.

Alex is helping Sam prepare for a MRI so they can figure out what is causing Sam's memory loss and headaches.

Somewhere else in National City, James Olsen and Lena are talking about a potential date when they catch Morgan Edge, and the three offer a strained second before Edge drives off.

Edge is driving not far off when the gas pedal sticks and the vehicle keeps moving forward. It turns out that somebody has taken control over the vehicle. Luckily for Edge, he's ready to exit out of the storage compartment before the vehicle crashes off of a dock.

Upset, Edge bursts into CatCo blaming Lena for hacking his vehicle. Edge cautions Lena that she should be prepared to complete what she began, expressing that he "never loses." Edge is expelled from the premises and prohibited from CatCo.

Sam's MRI is done, and Alex doesn't see anything amiss with the images. Alex reveals to her that they'll have to send the pictures to an authority alongside a blood test. While taking the blood test, Sam communicates her guilt over lying to Lena about skipping work to manage her own health.

Alex offers Sam some consolation and persuades her to converse with Lena and Kara about what's been happening.

Eve gets some espresso for Lena, who starts writhing and frothing from the mouth in the wake of taking a taste. She's been poisoned. James heads out to the espresso truck and notification an obscure looking specialist fleeing. In the wake of pursuing him, the specialist is shot by a sharpshooter, preventing James from finding any solutions.

Kara flies Lena to the DEO where Alex discovers she's been poisoned with cyanide. Alex says they have to back her body off, so Kara utilizes her ice breath to back Lena's vitals off, saving her.

Edge is strolling to his vehicle when he's drawn closer by James dressed up as Guardian. James starts cross examining him, and Edge denies having anything to do with the poisoning.

J'onn tells Kara that Lena will be awakening soon and recommends Kara return her to CatCo.

Lena awakens with James and Kara close by. She advises the pair that she thought she had a fantasy about flying through the air with Kara, and they persuade her it was symptom of being poisoned.

James tells the women that the projectile used to murder the contract killer was made utilizing cutting-edge technology, and in the wake of doing some burrowing, Lena finds that L-Corp had been creating tech like it. She goes to a L-Corp improvement site, where her mom is waiting for her.

Lillian uncovers that she's the one that executed the hired gunman that poisoned Lena. She reveals to Lena that she anticipates taking out Edge, however Lena advises her to remain away.

Lena comes back to CatCo, where she's instantly drawn nearer by Alex and Sam. Sam reveals to her supervisor about the health issues she's been experiencing. Sam uncovers that her greatest dread is abandoning Ruby on Earth without an emotionally supportive network, to which Kara, Lena, and Alex offer their help.

Lena's out on her gallery when Kara strolls in and asks her what she needed to discuss before. Lena admits that she had recently tried to kill Morgan Edge. Lena at that point discloses to Kara that her mother is back around. Lena requests Kara's assistance with saving Edge from Lillian.

Lena and Kara go to a function that Edge is facilitating and can move beyond his security. Lena attempts to get Edge to admit that he tried to kill Lena, and one of Lillian's drones begins taking shots at him. Under tension, Edge confesses to everything: the lead poisoning and the poisoning of Lena.

Lillian approaches the two at the celebration and is vexed that her daughter didn't let her execute Morgan Edge. Lillian changes the drone into a robotic armor suit and is before long drawn nearer by Mon-El, who's shown up to help. The two fight with Kara while Edge takes Lena's voice recorder that has his confession.

Edge drives Lena on a foot chase before he's halted by James, who is prepared as Guardian. Lena gets her voice recorder back, and Mon-El and Kara defeat Lillian.

Edge is captured, and Lillian is removed on a stretcher.

Alex reveals to Sam that every last bit of her tests returned clear. No tumors or sickness were found. Sam's despite everything upset since she feels something isn't right, and Lena advises Sam to return home and invest energy with Ruby.

At the DEO, Mon-El approaches Kara and makes a notice to how well they functioned as a group. He discloses to her that he's focused on being the saint Kara instructed him to be.

Winn tells Kara and Mon-El that he's discovered four leads of expected Worldkillers, and Kara singles out the one named Julia Freeman as the one in her vision.




  • Alex's mention of working as a doctor in Seattle before joining the F.B.I. is likely a nod to Chyler Leigh's role as Lexie Grey in Grey's Anatomy and Private Practice.
  • Winn reveals Superman has already killed Zod (at least by 2018). This is a reference to the 2013 film Man of Steel.
    • However, Mon-El revealed Zod will return in the future.
  • The armored Lexosuit that Lillian uses at the gala is very similar to Lex's purple and green armored warsuit he wears often in the comics.
  • Mon-El mentions getting the idea to use Lillian's drone against her from a battle alongside Brainy against Computo. In the comics, Computo was a supervillain created by Brainiac 5.
  • Winn says, "Sorry, these are not the drones you're looking for." In Star Wars Episode IV: A New Hope, Obi-Wan Kenobi uses the Force to convince two Stormtroopers to overlook R2D2 and C-3PO by waving his hand and saying, "These aren't the droids you're looking for."
  • The title of this episode references the song from the musical Wicked.


  • The series takes place in the U.S., but at 6:54, the speedometer and odometer in Edge's car show speed and mileage in kilometers as used in Canada, where the series is filmed.
  • At the gala when Lena shows Edge the audio recorder, the way she holds it changes between shots.