Before the year ends, The Flash and Arrow will once again meet in a special two-parter episode. That meeting will usher in The CW's latest superhero television series, "Legends of Tomorrow." Read on for more details of the said crossover.

"Arrow" developer Marc Guggenheim went to Twitter last week and announced that this year's "Arrow" and "The Flash" crossover is happening in three weeks' time. With a very cool photo of the two superheroes flanked by characters from "Legends of Tomorrow" (and the hashtag used by Guggenheim, too), it's not too hard to deduce that the crossover is going to usher in the third DC show from the network.

Talking to Deadline earlier this month, Guggenheim expounded on the crossover, "There's a lot of things that are really cool about this year's crossover, one of which is the fact that there really is a true 2-part story unlike last year where it was two interconnected episodes where each had their own beginning, middle, and end. This is a big two-part event, one single bad guy, and it will very clearly launch 'Legends of Tomorrow.'"

But the producer-comic book writer was quick to point out that it will not be a "backdoor pilot" for the new show. It will still be an individual "The Flash" and "Arrow" episodes that just so happens to introduce more of the characters from The CW's upcoming offering.

This year, the crossover will start with an episode on "The Flash" on Dec. 1, titled "Legends of Today." In that episode, Vandal Savage (Casper Crump) visits Central City and attacks Kendra Saunders (Ciara Renée) and Cisco Ramon (Carlos Valdes). To help Kendra out, Barry Allen a.k.a. The Flash (Grant Gustin) hides her in Star City, asking Oliver (Stephen Amell) and his team to help out. Things get more complicated when Carter Hall a.k.a. Hawkman (Falk Hentschel) flies off with Kendra.

Things will wrap up nicely on the episode on "Arrow" on Dec. 2, titled "Legends of Yesterday." Oliver and Barry hide Kendra and Hawkman while trying to figure out how to best defeat Vandal. Malcolm (John Barrowman) tries to neatly patch things up by having a sit down with the two heroes and the supervillain but it does not necessarily pan out. Team Arrow and Team Flash get together to create a weapon against Vandal.

Watch what else happens when "The Flash" and "Arrow" air their two-parter crossover episodes on Dec. 1 and 2, respectively. "Legends of Tomorrow: is scheduled to debut in 2016, with no definite release date yet.