Arrow has cast David Cubitt as Mark Shaw, who takes on the mantle of Manhunter in the DC comics.

Cubitt is expected to appear in the third episode of Arrow season 3, reports THR. An A.R.G.U.S. operative in Corto Maltese, Mark will cross paths with Diggle.

An A.R.G.U.S. connection for Diggle makes sense, as he learned at the end of season 3 that he is set to become a father, as ex-wife and on-again-off-again girlfriend Lyla Michaels — another A.R.G.U.S. operative — is pregnant.

In the DC comics, Manhunter is a name taken on by multiple characters, including Kate Spencer — the name of a prosecutor who died in season 2. The Manhunters are a sect of ancient crime fighters with ties to Green Lantern. Mark also has ties to the Suicide Squad, which appeared in Arrow season 2.

Cubitt’s other roles include Medium, Bates Motel, and Robbery Homicide Division.

Cubitt joins a growing list of casting additions to Arrow‘s third season. Recently, it was announced that the villain of season 3 will be legendary DC villain Ra’s al Ghul, though no casting information has been released yet.

Other additions to the new season of Arrow include Charlotte Ross as Felicity’s mother, J.R. Ramirez as Ted Grant/Wildcat, Brandon Routh as Ray Palmer/the Atom, Devon Aoki as Katana, and Peter Stormare as Vertigo.

The official synopsis for Arrow season 3 reads:

In the aftermath of this victory, Season 3 opens with Arrow now a hero to the citizens of Starling. Crime is down, people feel safer, and Captain Lance even calls off the Anti-Vigilante Task Force. Basking in his success, Oliver believes he can finally have a private life and asks Felicity out on a date. But the second Oliver takes his eye off the ball, a deadly villain reappears in Starling, forcing Oliver to realize that he can never be Oliver Queen — not as long as the city needs The Arrow.

Arrow season 3 premieres Wednesday, October 8 at 8:00 p.m. ET on The CW.