Supergirl The Flash Arrow and more crossover trailer is epic

The CW is getting all of it's DC superheroes together for one massive week of crossovers. And it's going to be pretty epic.

Supergirl, Arrow, The Flash and the cast of Legends of Tomorrow are all going to be appearing in the same four special episodes to be broadcast from the 28th of November to the 1st of December.

These canny folks will be teaming up to fight the might of The Dominators - an alien race which is up to no good. And you can get a taste with this trailer.