Arrow is introducing another DC Comics character — and he'll have strong ties to Diggle.

Medium star David Cubitt, who played Detective Lee Scanlon on the CBS procedural, has landed a meaty guest role in the CW comic-book drama's third season as Mark Shaw, who becomes Manhunter, The Hollywood Reporter has learned. Cubitt is slated to appear in the third episode.

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Who is Mark Shaw? In the DC comics, he is one of many who take on the Manhunter name. When the character makes his Starling City entrance, he will be an A.R.G.U.S. operative in Corto Maltese who crosses paths with Diggle. In comic lore, Mark has a connection to the Suicide Squad, as do Diggle and Oliver. In the past there have been nods to Manhunter on Arrow; in several episodes, a Starling City district attorney named Kate Spencer played a pivotal role in the mythology before she was killed in late season two. (One of the characters who becomes Manhunter in the comics has the same name.)

English-born Canadian actor Cubitt is the latest to board the upcoming season of Arrow, which will introduce prominent DC villain Ra's al Ghul as the main bad guy.

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"We have a really clever way of doing Ra's this year that is true to the comic-book origins but different from the way Ra's was portrayed in the [director Christopher] Nolan movies. You don't want to compete with Batman Begins, even though we've always said Batman Begins was a big influence on us," Arrow executive producer Marc Guggenheim told a handful of reporters at Comic-Con. "We really wanted our Ra's to be very different — at least our own Arrow-ified version."

Other key additions to the season include the Atom/Ray Palmer (Brandon Routh), Wildcat/Ted Grant (J.R. Ramirez), Felicity's mother (Charlotte Ross), Maseo (Karl Yune), Katana (Devon Aoki) and a new Count Vertigo (Peter Stormare).

Cubitt is repped by Resolution, Kirk Talent Agencies and Open Entertainment. He recently recurred as Norma Bates' late husband on Bates Motel and has several films, including Kit Harington's Seventh Son, in post. Arrow returns Oct. 8 on The CW.

Email: Philiana.Ng@THR.com

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