In the DC Comics, Boomerang/Harkness is a recurring foe of the Flash whose signature weapons are specialized boomerangs that he wields with incredible skill. On the page, he has also been associated with the Suicide Squad. On Arrow, Harkness will be a former A.R.G.U.S operative, highly skilled in martial arts and espionage, with a deadly thirst for vengeance against his former employers.

The character will be introduced in the seventh episode of the upcoming third season, and then continue in the eighth episode — which is when spin-off star The Flash crosses over into Starling City. In recent weeks, Arrow has also cast a Carrie Diaries vet as a love interest for Thea, and a Riddick alum as mega-villain Ra’s al Ghul. And for more on The Flash, check out our quick rundown of how The CW made the spin-off. The Flash debuts Tuesday, Oct. 7 and Arrow returns Wednesday, Oct. 8. Here’s Captain Boomerang from the comics: