ABC's Captain America spinoff Agent Carter is starting to flush out its cast.

Dollhouse alum Enver Gjokaj has booked a series regular role on the drama starring Hayley Atwell, The Hollywood Reporter has learned.

Based on the one-shot on the Iron Man 3 DVD, the drama, from showrunners Tara Butters and Michele Fazekas (Resurrection), stars Atwell and takes place a year after the events of Captain America: The First Avenger. It follows Steve Rogers' (Chris Evans) girlfriend Agent Carter (Atwell) as she builds her career as a secret agent while the hero is frozen in ice.

Gjokaj will play Agent Daniel Sousa, who will meet Carter while she takes on a new role at the pre-SHIELD Strategic Scientific Reserve in New York City.

Agent Carter, which will air as a gap show between the first and second half of Agents of SHIELD's sophomore run, is set in 1946. Peace has dealt Carter a serious blow as she finds herself marginalized when the men return home from fighting abroad. Working for the covert SSR, Peggy must balance doing administrative work and going on secret missions for Howard Stark all while trying to navigate life as a single woman in America, in the wake of losing the love of her life &mdash Steve Rogers.

Steve McFeely, Christopher Marcus and Marvel's Jeph Loeb exec produce. Captain America: Winter Soldier directors Anthony and Joe Russo will helm episodes two and three of the series. Captain America: The First Avenger helmer Joe Johnson could follow with episode four.

The role continues Gjokaj's relationship with the Marvel universe. He had a minor role as a "young cop" in Marvel's The Avengers. He most recently had an arc on CBS' Extant, TNT's Rizzoli & Isles, Lifetime's Witches of East End and AMC's The Walking Dead. His breakout role came in Fox's Dollhouse, which was produced by Agents of SHIELD exec producers Joss Whedon, Jed Whedon and Maurissa Tancharoen. He's repped by ICM Partners, Suskin Management and Jackoway Tyerman.

A specific premiere date for Agent Carter has not yet been determined, but it will air in Agents of SHIELD's slot on Tuesdays at 9 p.m. when the latter show goes on its winter hiatus.

Email: Lesley.Goldberg@THR.com

Twitter: @Snoodit