Stephen Amell, Grant Gustin

Arrow will welcome some new faces from The Flash universe in an upcoming episode!

Though Barry Allen (Grant Gustin) will not be returning to Starling City, both Danielle Panabaker and Carlos Valdes, who play two members of S.T.A.R. Labs in the Flash pilot, "make an important appearance in Episode 19 of Arrow," executive producer Marc Guggenheim revealed to press on Monday.

On the Arrow spin-off, Panabaker plays Caitlin Snow, a bioengineer who lost her fiancé during an explosion at S.T.A.R. labs, while Valdes plays Cisco Ramon, a mechanical engineering genius and the youngest member of the team of scientists at the lab. Caitlin Snow also happens to be the name of DC's latest incarnation of villain Killer Frost, while Cisco Ramon goes on to become Justice League's Vibe.

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"This was something that really came about because obviously Barry is in a coma at the end of Episode 9," Guggenheim said. "That pretty much made it impossible for Barry to appear in [Episode 20, as originally planned]... The idea of bringing in those characters really, really appealed to us because it allowed us to honor our original intention [of] doing something Flash-related around Episode 19 or 20 without having comatose Barry and basically paying Grant Gustin a lot of money to sit around with his eyes closed just unconscious the whole episode... This episode is really cool. It allows us to further flesh out the Flash universe in Arrow."

The episode was co-written by Greg Berlanti, Andrew Kreisberg and DC Chief Geoff Johns, who are all executive-producers on Flash.

Are you excited to see the Flash-Arrow crossover?

Arrow airs Wednesdays at 8/7c on The CW.

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