The CW released an extended trailer for the upcoming crossover event between The Flash and Arrow, which reveals that Captain Cold and Heat Wave will make an appearance in the episode! This episode looks like it will have a good sense for the humor and character moments that will be on display in the crossover. From what we have seen in previous trailers, it looks like Flash and Arrow will duke it out. So who do you think would win in an epic confrontation? Arrow or Flash? Check out the trailer below.