Supergirl: Season 3
Season 3 Lore Primer
Key plot threads, lore context, and character stakes you need to remember before diving into this season.
- Directly follows the overarching narrative developments of Supergirl Season 2.
- Faction dynamics and core character alliances shift under escalating external stakes.
- Crucial mysteries introduced previously reach key turning points and narrative reckonings.
- Sets up serialized story arcs that build directly toward the climactic season finale.
Episode Guide
Season 3 Progress Shield
Girl of Steel
Oct 9, 2017
Kara deals with the loss of Mon-El by focusing all her energy on being Supergirl and the mysterious new threat against National City. Alex confesses a secret to Maggie about their
Triggers
Oct 16, 2017
Psi, a thief with psychic powers, attacks National City. Able to immobilize people by tapping into their worst fears, Psi proves a formidable opponent for Supergirl. Meanwhile, Jam
Far From the Tree
Oct 23, 2017
Eliza throws Alex and Maggie a wedding shower, which causes Maggie to reach out to her estranged father. Supergirl joins J’onn on a personal mission.
The Faithful
Oct 30, 2017
Kara investigates a secretive new group whose leader, Thomas Coville, has a mysterious connection to Supergirl. Meanwhile, Samantha feels like she's letting Ruby down, and J'onn co
Damage
Nov 6, 2017
When multiple children get sick from lead poisoning, Morgan Edge points the finger at Lena and blames her creation of the lead bomb she made to save National City from the Daxamite
Midvale
Nov 13, 2017
Kara and Alex head home to Midvale for a little R&R. While there, Kara recalls a painful memory of a childhood friend's death and how that traumatic experience brought the Danver s
Wake Up
Nov 20, 2017
When Winn and the team discover an alien ship has crash landed deep underwater beneath National City, Kara/Supergirl is called in to investigate. Meanwhile, Hank attempts to bond w
Crisis on Earth-X (I)
Nov 27, 2017
Barry and Iris’s wedding brings the gang together, but things go awry when villains from Earth-X attack the ceremony. All of the superheroes band together with help from their supe
Reign
Dec 4, 2017
Supergirl investigates a mysterious symbol popping up all over National City, tracing its origins back to an ancient prophecy and the mark of the World Killer, Reign. Meanwhile, th
Legion of Superheroes
Jan 15, 2018
Struggling to heal from her injuries inflicted by Reign, Supergirl remains in a dreamlike state, unable to be reached. Mon-El recruits one of the Legion members, Brainiac-5, to try
Fort Rozz
Jan 22, 2018
As Reign continues to terrorize the city, Supergirl teams up with Saturn Girl, and the two recruit Supergirl’s former enemies, Livewire and Psi, to form a team for a mission to For
For Good
Jan 29, 2018
Someone tries to kill Morgan Edge and he barely survives. He accuses Lena of being behind the attempt and vows to destroy her. When Lena fears her hatred for Morgan will take her t
Both Sides Now
Feb 5, 2018
The DEO captures a second Worldkiller, Purity. Supergirl and Alex use very different methods of interrogation with Purity in the hopes of finding out how to defeat Reign. However,
Schott Through the Heart
Apr 16, 2018
When Winn’s father dies, his estranged mother, Mary, reappears trying to reconnect and to explain why she abandoned him all those years ago. Winn is too embittered from his rough c
In Search of Lost Time
Apr 23, 2018
Myr'nn inadvertently causes psychic disturbances at the DEO; Supergirl must work with J'onn to contain the chaos; Mon-El begins training Kara in fighting techniques he's learned in
Of Two Minds
Apr 30, 2018
Supergirl and Imra have different ideas on how to stop the third Worldkiller, Pestilence. However, when both Alex and Winn are seriously injured by Pestilence, Supergirl and Imra t
Trinity
May 7, 2018
Still reeling after learning about Lena’s secret, Supergirl asks Guardian for a favor that could alter his relationship with Lena forever. Meanwhile, with all three Worldkillers un
Shelter from the Storm
May 14, 2018
When Reign starts hunting Ruby, Supergirl and Alex work together to keep her safe. Supergirl and J'onn look to Sam’s mother for advice on how to stop Reign and come away with some
The Fanatical
May 21, 2018
When Tanya, a disciple of Coville's, escapes from what's left of his cult, she gives Kara and James a journal that could hold the key to saving Sam. Someone learns Guardian's ident
Dark Side of the Moon
May 28, 2018
Supergirl is stunned to discover that a part of Krypton survived. Meanwhile, Alex is attacked while out with Ruby, and Lena considers how far she will go to keep Reign contained.
Not Kansas
Jun 4, 2018
Kara makes a major life decision. Meanwhile, J'onn finds out that special DEO-caliber guns have hit the streets of National City.
Make It Reign
Jun 11, 2018
Supergirl learns the true depth of Selena's nefarious plans for Earth. Supergirl, Mon-El and Alura must devise a plan to stop her before Selena gets to Earth. J'onn prepares to say
Battles Lost and Won
Jun 18, 2018
Supergirl and team take on Selena in an epic battle for Earth.