Fans from both 'The Flash' and 'Arrow' teams have been waiting for the next crossover between the DC superhero universe, and their long wait is almost over.  

The crossover is expected to air two nights in a row, and it will feature a whole lot of superheroes aside from Arrow and The Flash. Executive Producer Greg Berlanti teases its fans of what will happen in the most anticipated merging of the shows. According to him, the two episodes are aptly entitled 'Legends of Today' and 'Legends of Tomorrow,' as these will present the cast of the new CW DC spinoff 'Legends of Tomorrow.'

The plot of the first episode includes an immortal villain Vandal Savage (Casper Crump) as he eyes Hawkgirl. Protecting his fellow superheron, Barry hides Hawkgirl in Oliver Queen's hometown. The action builds up until the second part, where most of the scenes are set in Central City.

In his interview with TV Line, Berlanti explains that the two episodes should be treated as one entire movie instead of two separate episodes. The show runner shares, "Because Flash was in its first year last year, we tried with each to make it still feel like a Flash episode and still feel like an Arrow episode. This year, we wanted to really blend them and really make it feel like, 'What if you were to do a two-hour film with all these characters?' That was our focus." Berlanti also stresses that though there are parts in the show that are distinctly from 'The Flash' fans could expect that there is really a centralized plot throughout the crossover.

Aside from the cast being in the same scene, Berlanti says that viewers could expect the biggest emotional story they have ever shown on 'Arrow.' Though he refused to spill details, he hinted that there will be a moment comparable to last year's crossover where Oliver ran into a former lover without knowing that she had been raising his child.

The two-episode crossover will be aired on December 1 and 2 on CW.