CW has released a first look, and a short promo for the 2 December episode of The Flash titled Flash vs. Arrow.
The episode pits Barry against the city, after he is sent into a rage by a supervillain with the ability to manipulate the emotions of others. As the police start a task force to take him down, it seems only Arrow can talk sense into him.
Arrow star Stephen Amell and The Flash star Grant Gustin in an interview teased what to expect when the heroes of Starling City and Central City come together.
Gustin told IGN: "I was talking about this yesterday with a friend; about how Oliver and Barry are so different and me and Stephen are just really different. We really get along outside of work and it's been fun to show Barry and Oliver kind of butting heads.
"We're seeing them learn how to work together, but it's really funny because they're so different and the conversations they have are hilarious." He added.
Going by reports, a really big moment for Oliver Queen will happen during the crossover storyline, especially on The Flash episode.
Stephan Amell revealed, "It's my idea. I can't tell you anything about it other than that it relates to Central City. When I saw it in the Flash script, it ended up being actually quite gratifying."
The actor teased an "Arrow-centric moment" in the much awaited mash-up.
He said: "I can't say anything about what it has to do with other than that the crossovers... We are very much guests in Central City and very much the rogue team in Central City. Just as much as Grant and the Flash team are guests here. We talk and we delve into the differences between Central City and Starling City but this particular moment is very much an Arrow-centric moment."
Also, The Flash's villain Boomerang (played by Spartacus vet Nick Tarabay) has a surprising connection to Starling City.
Executive producer Greg Berlanti told Tvline: "He's got a relationship to one of our recurring [Arrow] characters, but I shouldn't say who."
The report also states that the Weather Wizard, was killed by Barry in the pilot episode, whereas his brother Mark Mardon survived the plane crash. "He also possesses the same powers, but lethally refined, weather-controlling powers. Oh, and he wants Detective West (AKA Clyde's killer) dead."
Also, a special extended sneak-peek will be aired on the upcoming episode of The Flash titled Power Outrage.
Watch the promo here:
Here are all the promotional pictures released by CW