Katie Cassidy Rodgers will play the role of Earth-1's Laurel Lance, the original Black Canary, in "Crisis on Infinite Earths," according to the event's showrunner, Arrow co-creator Marc Guggenheim. Earth-1 Laurel died back in Arrow's fourth season, and since then, Cassidy-Rodgers has played an Earth-2 version of herself. "Black Siren," who came to Earth-1 along with a number of other villains during Zoom's attack on Central City in The Flash's second season, had one of the Arrowverse's most engaging redemption arcs, finally becoming a key member of Team Arrow in season 7. This season, she has been driven by grief -- because in the season 8 premiere of Arrow, she watched her world being erased from existence and only survived because Oliver and Diggle brought her with them back to Earth-1.
Guggenheim did not make clear how the Earth-1 Laurel would play into "Crisis on Infinite Earths," although given that the Legends of Tomorrow are appearing in the crossover and Jonah Hex has been confirmed to have a role, it stands to reason that time travel, rather than reviving her from the grave, is likely the answer.
Guggenheim also clarified that while Earth-1's Laurel Lance will appear in the crossover, the role of Laurel in the Green Arrow and the Birds of Prey spinoff will still be fulfilled by Black Siren.
Earth-1 Laurel in Crisis. Earth-2 Laurel in spin-off. https://t.co/EN3es1gSzx— Marc Guggenheim (@mguggenheim) November 15, 2019
"Crisis on Infinite Earths" has loomed over the Arrowverse for years. The series premiere of The Flash featured an allusion to the hero disappearing amid red skies in the year 2024. During the original comics event, red skies were a sign of doom to come to a world during the Crisis. At the end of last season, a couple of things happened: The Monitor (LaMonica Garrett), who had appeared in "Elseworlds," reappeared and revealed that Oliver Queen was destined to die in the Crisis...and the future newspaper at STAR Labs rolled back the expected date of the Crisis from 2024 to 2019.
In the comics, Crisis on Infinite Earths centered on a battle between the combined superheroes (and even some villains) of the DC multiverse and an immortal, cosmic threat known as the Anti-Monitor. Like The Monitor, the Anti-Monitor will be played by LaMonica Garrett in the Arrowverse. As the Anti-Monitor destroys realities, he replaces their positive matter energy with antimatter, growing his own power and sphere of influence. He was eventually stopped by the sacrifices of several heroes, including The Flash and Supergirl, as well as the merging of multiple universes to save reality by becoming a single, unified timeline. Fans have long wondered whether the events of "Crisis on Infinite Earths" might bring Supergirl and even Black Lightning to Earth-1, where the rest of the series take place. The crossover will also feature guest appearances by Tom Welling as Clark Kent, Erica Durance as Lois Lane, John Wesley Shipp as the Flash of Earth-90, Johnathon Schaech as Jonah Hex, Kevin Conroy as Bruce Wayne, and Ashley Scott as The Huntress.
“Crisis on Infinite Earths” kicks off on Sunday, December 8 on Supergirl, runs through a Monday episode of Batwoman and that Tuesday’s episode of The Flash. That will be the midseason cliffhanger, as the shows go on hiatus for the holidays and return on January 14 to finish out the event with the midseason premiere of Arrow and a "special episode" of DC's Legends of Tomorrow, which launches as a midseason series this year and so will not have an episode on the air before the Crisis.