Followers of The CW's DC television shows are no strangers to crossovers between their favorite superheroes. The Green Arrow/Oliver Queen, Flash/Barry Allen, Supergirl/Kara Danvers and the folks from "Legends of Tomorrow" have shared TV screens a few times now, and a new one has been teased recently.

Executive producer Marc Guggenheim recently posted a photo on Twitter showing The Flash (Grant Gustin) crossing over on "Arrow." In the snapshot, the Scarlet Speedster was seen sticking a post-it note on a computer screen on a still unknown police officer's desk, while said policeman was standing close and talking to someone on the phone.

Check out the photo below. According to Guggenheim, the episode 11 crossover is "the fastest" they have ever done between the two shows. It's possible that viewers won't even hear The Flash speak, and it's still unknown whether he dropped by Starling City on his own volition or if someone sought his help on an important matter.

Episode 11 of "Arrow" Season 5 is titled "Second Chances" and will showcase Talia al Ghul (Lexa Doig) helping Oliver (Stephen Amell) take down Kovar (Dolph Lundgren), SpoilerTV reported. However, she wants something in return for her assistance and Oliver will not like it. The episode will also reveal via flashbacks how Oliver knew Talia.

Felicity's (Emily Bett Rickards) attempts to hack the NSA for Diggle's (David Ramsey) freedom will backfire when she gets flagged, and an unknown foe will track her down. Curtis (Echo Kellum) also discovers a female vigilante named Tina Boland (Juliana Harkavay) who's doing more damage than good in the country.

The CW recently released a "Getting Good" trailer featuring Oliver and Prometheus' final showdown. You can watch the sneak peek in the end of this report.

"Arrow" viewers are wondering how Prometheus got wind of Black Siren (Katie Cassidy) and that she was kept under lock and key in S.T.A.R. Labs. There are speculations that Prometheus is Tommy Merlyn (Colin Donnell), who expressed a strong dislike over Oliver's kills when they were still friends, according to Forbes. Tommy may want to punish Oliver for all the awful things the latter did in the past.

"Second Chances" will air on Wednesday, Feb. 1 at 8:00-9:00 p.m. ET. Any theories on why The Flash dropped by in Starling City? How do you think Oliver and Prometheus' much-awaited showdown will play out? Sound off in the comments section below!

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Tags Arrow, The flash, Stephen amell, Grant gustin