This epic event will begin with Barry Allen and Cisco Ramon seeking Kara’s help with an alien invasion on their Earth, which will take place at the conclusion of the “Supergirl” episode titled “Medusa”, which is scheduled to air on The CW on Monday, November 28.
The next night, Tuesday, November 29, Supergirl will appear on the episode of “The Flash” titled “Invasion”:
When aliens called the Dominators attack Central City, Barry (Grant Gustin) speeds over to Star City to ask the Green Arrow (guest star Stephen Amell) for help in stopping them. Realizing the battle against the Dominators is bigger than they thought, they track down the Legends of Tomorrow, and Barry and Cisco (Carlos Valdes) create a breach to bring back a secret weapon – Supergirl (guest star Melissa Benoist). Once all of the super friends are assembled, they come up with a plan to attack but a shocking secret related to Flashpoint is revealed and suddenly no one is sure who they can trust. Meanwhile, Wally (Keiynan Lonsdale) wants to join the battle against the aliens but Iris (Candice Patton) tells him he’s not ready.
The following night, Wednesday, November 30, the story continues in the 100th episode of “Arrow” in an episode also titled “Invasion”:
Oliver (Stephen Amell) wakes up to a life where he never got on The Queen’s Gambit. Robert (guest star Jamey Sheridan) and Moira Queen (guest star Susanna Thompson) are alive and well. Laurel (guest star Katie Cassidy) is his loving fiancée and their wedding is imminent. Everything seems perfect, but Oliver starts to notice small imperfections that make him question this new reality. Meanwhile, Felicity (Emily Bett Rickards) and the recruits take on a new threat with help from The Flash (guest star Grant Gustin) and Supergirl (guest star Melissa Benoist).
The “Invasion” saga concludes on “DC’s Legends of Tomorrow” on Thursday, December 1:
After learning the Dominators’ plan for the world, the Legends must work together with The Flash (guest star Grant Gustin), Supergirl (guest star Melissa Benoist) and Green Arrow (guest star Stephen Amell) to kill them once and for all. Meanwhile, Stein (Victor Garber) figures out, with the help of others, how the team can terminate the Dominators, but is distracted by the aberration he realizes he created in 1987.
So, be sure to tune in to The CW across all four nights, starting with “Supergirl” on Monday, November 28 for the “Invasion” crossover event.