The "Firefly" star has joined The CW's breakout hit as a "dangerous" new addition.

Arrow is adding a fierce female with major geek cred to the mix for season two.

Firefly and Terminator: The Sarah Connor Chronicles star Summer Glau has booked a recurring role on The CW's breakout action drama toplined by Stephen Amell, The Hollywood Reporter has learned.

Glau will play the "enigmatically beautiful" and "dangerous" Isabel Rochev, vp acquisitions at Stellmoor International, a company looking to take over Queen Consolidated. She will first appear in the premiere.

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On Arrow, not much is known of Isabel, except as part of a list of names in Robert Queen's book of corrupt and powerful people in Starling City. (In the DC Comics universe, the villainous Isabel — who appears in several Green Arrow issues — rose from being a slave to running Queen Industries, with the desire to return the company back to its former glory.)

Arrow — which began production earlier this week — has already introduced a slew of DC Comics characters, including Deadshot (Michael Rowe), China White (Kelly Hu), Malcolm Merlyn (John Barrowman) and Deathstroke/Slade Wilson (Manu Bennett), and often taps genre favorites like Seth Gabel (Fringe) and Tahmoh Penikett (Battlestar Galactica) to fill roles.

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Arrow will be hitting San Diego's Comic-Con for the second year on Saturday, July 20, from 5:15-6 p.m. to preview the new season with executive producers Greg Berlanti, Marc Guggenheim and Andrew Kreisberg, as well as castmembers Amell, Katie Cassidy, Colton Haynes, Emily Bett Rickards and David Ramsey. (Haynes, Rickards and Bennett were promoted to series-regular status for season two.)

Glau, repped by UTA and The Schiff Co., starred as River Tam in cult favorites Firefly and Serenity. Other notable credits include Dollhouse, The Cape, Alphas, The 4400, Grey's Anatomy, Chuck and The Big Bang Theory.

Arrow returns Oct. 9 on The CW.

E-mail: Philiana.Ng@THR.com

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