| "Crisis on Earth-X" | |
|---|---|
| Arrowverse crossover event | |
.jpg) Promotional poster and home media cover | |
| Story by | |
| Part 1: Supergirl | |
| Episode title | "Crisis on Earth-X, Part 1" |
| Episode no. | Season 3 Episode 8 |
| Directed by | Larry Teng |
| Teleplay by |
|
| Production code | T13.20658 |
| Original air date | November 27, 2017 |
| Episode chronology | |
| Part 2: Arrow | |
| Episode title | "Crisis on Earth-X, Part 2" |
| Episode no. | Season 6 Episode 8 |
| Directed by | James Bamford |
| Teleplay by | |
| Production code | T27.13458 |
| Original air date | November 27, 2017 |
| Episode chronology | |
| Part 3: The Flash | |
| Episode title | "Crisis on Earth-X, Part 3" |
| Episode no. | Season 4 Episode 8 |
| Directed by | Dermott Downs |
| Teleplay by | Todd Helbing |
| Production code | T27.13408 |
| Original air date | November 28, 2017 |
| Episode chronology | |
| Part 4: Legends of Tomorrow | |
| Episode title | "Crisis on Earth-X, Part 4" |
| Episode no. | Season 3 Episode 8 |
| Directed by | Gregory Smith |
| Teleplay by | |
| Production code | T13.20608 |
| Original air date | November 28, 2017 |
| Episode chronology | |
| Crossover chronology | |
| Preceded by | "Invasion!" |
| Followed by | "Elseworlds" |
"Crisis on Earth-X" is the fourth Arrowverse crossover event, featuring episodes of the live-action television series Supergirl, Arrow, The Flash, and Legends of Tomorrow on The CW. The crossover began on November 27, 2017, with Supergirl and Arrow, and concluded on November 28, with The Flash and Legends of Tomorrow. In "Crisis on Earth-X", Barry Allen and Iris West's friends come to Central City for their wedding, only for the proceedings to be interrupted by interlopers from the analogous universe of Earth-X, where the Axis powers claimed victory in World War II.
Development for a crossover of the four series began in December 2016 after the release of the previous crossover, "Invasion!". The premise and title of the crossover were revealed in September 2017 as production on the episodes began; elements from the animated web series Freedom Fighters: The Ray were part of the crossover, including the live-action appearance of Raymond Terrill / The Ray, the Freedom Fighters, and the New Reichsmen. A subsequent crossover aired the following year, titled "Elseworlds".[1]