The CW network has released the synopsis for episode #208 of The Flash, which you can check out below. The installment, titled “Legends of Today,” is officially described as follows:
PART ONE OF THE EPIC CROSSOVER WITH “ARROW” — In its second major event with “Arrow,” Vandal Savage (guest star Casper Crump) arrives in Central City and sets his sights on Kendra Saunders (guest star Ciara Renée). After Vandal attacks Kendra and Cisco (Carlos Valdes), they turn to Barry (Grant Gustin) for help. Realizing how dangerous Vandal is, Barry takes Kendra to Star City and asks Oliver and team to hide her until he can figure out how to stop Vandal. However, things quickly go from bad to worse when a man with wings AKA Hawkman (guest star Falk Hentschel) shows up and flies off with Kendra. Meanwhile, Harrison (Tom Cavanagh) develops a serum to make Barry run faster and asks Jay (guest star Teddy Sears) to test it out.
The Flash “Legends of Today” was directed by Ralph Hemecker with story by Greg Berlanti & Andrew Kreisberg and teleplay by Aaron Helbing & Todd Helbing. The episode airs Tuesday, December 1, at 8pm on The CW.