While we won't know for a few more months if The CW will pick up the Arrow spin-off The Flash to series, series co-creator and executive producer Greg Berlanti revealed new details about the show in a recent interview. He talked about how the spin-off will be more of a sci-fi series, while teasing plans to keep Grant Gustin on Arrow, if The CW doesn't issue a series order for The Flash.

When asked about how The Flash will be different from Arrow, the executive producer had this to say.

"Barry (Grant Gustin) is different from Oliver (Stephen Amell). He's a man of science and has more of a sci-fi bent, whereas Arrow has a bit more of a crime bent. We often talk about how Oliver comes off like a pessimist, but deep down he's an optimist and has hope. Barry lost his mother at a very young age, his father was sent to prison for murdering his mom, he went through a lot of stuff - on the surface he's bubbly and upbeat and seems like an optimist, but deep down maybe there's no hope left. So they're a really nice contrast to each other and the show functions in that way, I think. Certainly in the pilot script Barry has an effervescence and a lightness, but there's still a dark well beneath that."

He also revealed that more superheroes from the DC Comics will be used in the spin-off, including Harrison Wells and the S.T.A.R. Labs facility.

"We've talked a lot on Arrow about the particle collider and Harrison Wells and S.T.A.R. Labs and so you'll see S.T.A.R. Labs as an active part of the show."

Grant Gustin's Barry Allen was introduced on two Season 2 episodes of Arrow last year, showing how he transforms into The Flash. Even if The CW doesn't pick up the series, Greg Berlanti revealed they still plan on using the character in Arrow.

"Fingers crossed we don't screw it up and he gets his own show! If he didn't, I don't think we would ever want to let Grant go. He's too valuable. That would be our hope, I think - no matter what, to keep Barry part of the universe."

The Flash pilot begins production in a few weeks, with David Nutter directing from a script by Greg Berlanti, Andrew Kreisberg and Geoff Johns.