Last year's two-night crossover event on "The Flash" and "Arrow" drew huge audiences and greatly boosted the ratings of both shows. Due to that success, the crossover has now become an annual event. And this year the stakes are even higher. An immortal villain comes to town and all hell breaks loose. The threat this year definitely requires both Team Flash and Team Arrow to work together. On top of that, this two part episode will also the launch The CW's new show "Legends of Tomorrow", a time traveling journey with some of DC's best heroes and villains. 

This two-night crossover event kicks off on December 1, staring with "The Flash":

In its second major crossover 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, they turn to Barry 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 develops a serum to make Barry run faster and asks Jay (guest star Teddy Sears) to test it out.

The crossover event will conclude on December 2 with "Arrow":

Oliver and Barry Allen take Kendra Saunders and Carter Hall to a remote location to keep them hidden from Vandal Savage while they figure out how to defeat him. Malcolm arranges a meeting between Vandal, Green Arrow and The Flash that doesn’t go as planned. Meanwhile, Felicity, Thea, Diggle and Laurel work with Team Flash to come up with a weapon powerful enough to destroy Vandal Savage.

Both of these episodes, respectively titled "Legends of Today" and "Legends of Yesterday" will set up the spinoff show "Legends of Tomorrow", which will feature Vandal Savage as the major villain of that series. His introduction on both shows will catalyze Rip Hunter ("Doctor Who's" Arthur Darvill) to assemble a team of superheroes, which so far includes Ray Palmer (Brandon Routh), Sara Lance (Caity Lotz), Hawkgirl (Ciara Renee), Hawkman (Falk Hentschel), Captain Cold (Wentworth Miller), Heat Wave (Dominic Purcell) and Firestorm (Victor Garber/Franz Drameh). 

"The Flash" and "Arrow" crossover event begins December 1 at 8/9C on The CW.

Entertainment journalist who’s passionate about science fiction, superheroes, and all things nerdy. Regular Comic Con attendee, co-founder of The Marvel Report, co-host of The Flash Podcast and the Peggy Carter Podcast. Assistant editor at CBR, contributing writer to Tracking Board and HitFix Harpy. Obsessed with British accents, strong female characters, Sherlock, and Steve Rogers.