'Arrow' Season Finale Trailer Gives First Look at The Flash

The "Arrow" season finale airs Wednesday night on The CW at 8 p.m. ET and we have the trailer, titled "Unthinkable." But don't blink! At the very end, you can catch a glimpse of The Flash (Grant Gustin). It's really quick but, ya know, that's how he rolls. The end of the trailer promises an "exclusive first look at The Flash" so we're hoping they give us a little more.

It's obviously a perfect tie-in because Barry really digs "Arrow."

“Barry Allen is a Central City assistant police forensics investigator who arrives in Starling to look into a series of unexplained robberies that may have a connection to a tragedy in his past. A comic book fanboy, Barry is obsessed with the Arrow unaware that working with Oliver and Felicity to solve the crime has brought him right into the dangerous world of the vigilante.”

"The Flash" will star Grant Gustin, Jesse L. Martin, Rick Cosnett, Danielle Panabaker, Candice Patton, Carlos Valdes, Tom Cavanaugh, John Wesley Shipp, Michelle Harrison, and Patrick Sabongui. It will premiere this fall.

Check out the promo for tomorrow night's "Arrow" and let us know if you're excited for "The Flash." We sure are!

Synopsis for "Unthinkable:"
OLIVER MUST DECIDE ONCE AND FOR ALL IF HE’S A KILLER OR A HERO — Slade (Manu Bennett) moves forward with his plan to kill one more person in Oliver’s (Stephen Amell) life. While Oliver has fought all year to be more than the killer he once was, when Slade kidnaps someone close to Oliver’s heart, Oliver is pushed to the edge and realizes sometimes it takes doing the unthinkable to stop the monster. Meanwhile, Diggle (David Ramsey) takes on Amanda Waller (guest star Cynthia Addai-Robinson) with a little help from some friends, and Thea (Willa Holland) turns to Roy (Colton Haynes) in her time of need. John Behring directed the episode with story by Greg Berlanti and teleplay by Marc Guggenheim & Andrew Kreisberg (#223).

-Larissa Mrykalo