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 super friends like Citizen Cold, The Ray, Felicity Smoak, Iris West and Alex Danvers to take on their most formidable villains yet. Earth’s mightiest heroes – Green Arrow, Supergirl, The Flash and White Canary – lead their teams into battle to save the world. The crossover continues on Arrow S06E08 Crisis on Earth-X (II), The Flash S04E08 Crisis on Earth-X (III) and DC's Legends of Tomorrow S03E08 Crisis on Earth-X (IV).
- Directed by
- Larry Teng
- Written by
- Jessica Queller, Robert Rovner, Andrew Kreisberg
Guest stars
Emily Bett Rickards
Felicity Smoak
Danielle Nicolet
Cecile Horton
Keiynan Lonsdale
Wally West / Kid Flash
Jesse L. Martin
Joe West
Candice Patton
Iris West
Dominic Purcell
Mick Rory / Heat Wave
Patrick Sabongui
Captain David Singh
Victor Garber
Dr. Martin Stein
Franz Drameh
Jefferson "Jax" Jackson / Firestorm
Robyn Bradley
Wedding Planner
- P
Paul Herbert
Scientist
Jessica Parker Kennedy
Caterer
All episodes — Season 3
Open season page
S3 E1Girl of Steel
Oct 9, 20176.942 min
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 impending nuptials. A citizen of National City has a mysteri
S3 E2Triggers
Oct 16, 20177.342 min
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, James and Lena are at an impasse, and Samantha starts her new j
S3 E3Far From the Tree
Oct 23, 20177.142 min
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.
S3 E4The Faithful
Oct 30, 20177.142 min
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 confesses an old secret.
S3 E5Damage
Nov 6, 20177.442 min
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 Daxamites. While Lena knows she never intended any harm, she fears t
S3 E6Midvale
Nov 13, 20177.942 min
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 sisters closer together.