The CW has released its promo (watch below) for the two-night crossover event with The Flash and Arrow. Beginning Tuesday, December 1, 2015 with “Legends of Today,” on The Flash, and concluding December 2, 2015 with “Legends of Yesterday,” on Arrow, the crossover sets up new spin-off, DC’s Legends of Tomorrow, which premieres mid-season. Here’s a description of the first half of the Flash/Arrow crossover:

The Flash 2×08 “Legends of Today” – PART ONE OF THE EPIC CROSSOVER WITH “ARROW” — 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 (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. Ralph Hemecker directed the episode with story by Greg Berlanti & Andrew Kreisberg and teleplay by Aaron Helbing & Todd Helbing

Watch the crossover promo trailer:

https://www.youtube.com/watch?v=0Acwr3f7RD4

Cinema Blend expects that once Legends of Tomorrow premieres on The CW sometime in 2016, there will be even bigger, badder, three-night crossover events:

The Flash hardly needed help from Arrow following its premiere in fall of 2014, as it found success with its own brand of superhero entertainment. The ensemble of characters pulled from Flash and Arrow to pad the Legends of Tomorrow lineup should guarantee an audience for the new show. With so many characters in common, future crossover extravaganzas involving all three shows are inevitable. In fact, as long as the three teams of characters don’t play any games of Six Degrees of Sexual Separation with each other, each crossover event could build upon a beautiful friendship between the series.

The CW has not yet announced when exactly in 2016 Legends of Tomorrow will be hitting the airwaves, but Amell’s tease of a three-night crossover event could mean that the spin-off will not follow either The Flash on Tuesday nights or Arrow on Wednesday nights. Hopefully for fans of the future Legends of Flarrow-verse, Legends of Tomorrow will land on a Monday or Thursday. A three-night crossover event won’t feel nearly as big or cinematic if it’s broken up by nights of Jane the Virgin or Reign.

What do you think? Are you a fan of The Flash and Arrow TV shows on The CW? Will you watch both nights of the crossover? Do you plan to check out the spin-off series, DC’s Legends of Tomorrow?