We told you back in July that The CW had announced that The Flash would be appearing in the new season of Arrow and that a backdoor pilot (an episode of an existing show that could  be considered a pilot for a spinoff show) was being planned that would hopefully result in the pickup of a new series.

That role has now been cast, and THR reports that it’s Grant Gustin who’ll be the new Barry Allen/Flash. We also now know that he’ll be appearing in three episodes of Arrow, numbers 8, 9, and 20, and that the last will be the backdoor pilot, which won’t air until spring.

All three Flash episodes will be written by Arrow co-creators Greg Berlanti, Andrew Kreisberg, and DC Entertainment‘s Geoff Johns — a writer/consultant on Arrow.

In Arrow, Barry Allen/Flash will be a Central City assistant police forensic investigator who comes to Starling City as part of an investigation. The big mystery for Arrow and Flash fans will be: will Flash have superpowers? I mean, come on, he’s The Flash. In the notably superpower-free zone of The CW’s Arrow, how exactly does one acquire super speed? According to Kreisberg, “There will be extraordinary events in the world and the characters will react in the same way.” Hoookay. The mind reels. We shall see.

We’ll definitely keep you posted.