Jocko Sims as Robert in Showtime's "Masters of Sex"

Jocko Sims as Robert in Showtime’s “Masters of Sex”

*Fans of Showtime’s “Masters of Sex” have already seen solid guest performances from Keke Palmer and Courtney B. Vance this season.

Set in the late 50s/early 60s, the series follows Dr. William Masters (Michael Sheen) and Virginia Johnson (Lizzy Caplan), and their pioneering research of human sexuality, which becomes complicated and ultimately impacted by their own personal relationship.

Coral (Keke Palmer) is asked to wash her hair with lice shampoo by Libby Masters (Caitlin Fitzgerald) in "Masters of Sex" (Season 2, Episode 4)

Coral (Keke Palmer) is asked to wash her hair with special lice shampoo by Libby Masters (Caitlin Fitzgerald) in “Masters of Sex” (Season 2, Episode 4)

Palmer played Coral, a nanny for the Masters household…until Mrs. Libby Masters’ insecurities about race cut her employment short. Vance played the chief of staff at a black hospital that temporarily housed Masters and his sex study after he fell out of favor with all of the white hospitals in town.

Dr. Hendricks (Courtney B. Vance) tries to convince Bill Masters (Michael Sheen) to keep pushing to integrate  his hospital Buell Green.

Dr. Hendricks (Courtney B. Vance) tries to convince Bill Masters (Michael Sheen) to keep pushing to integrate his hospital Buell Green.

With three episodes left, recurring star Jocko Sims is getting a lot of screen time as Robert Franklin, Coral’s brother and a member of the civil rights group CORE, whose office is in the same building as Master’s sex study.

Robert (Jocko Sims) confronts Libby (Caitlin Fitzgerald) about what she's actually willing to do as a CORE volunteer in "Masters of Sex" (Season 2, Episode 9)

Robert (Jocko Sims) confronts Libby (Caitlin Fitzgerald) about what she’s actually willing to do as a CORE volunteer in “Masters of Sex” (Season 2, Episode 9)

More importantly, Robert has a quiet way of challenging the hypocrisy, insecurity and self-righteousness of Libby Masters. That all came to a head in Sunday’s episode, which ended with Libby becoming a volunteer for CORE — not because of any deep desire to fight for black civil rights, but more as a selfish, rebellious move to shatter people’s perception of her as a go-along gal – a trait she has carried for too long in her marriage.

Actor Jocko Sims attends Showtime 2014 Emmy Eve Soiree at Sunset Tower on August 24, 2014 in West Hollywood, California

Actor Jocko Sims attends Showtime 2014 Emmy Eve Soiree at Sunset Tower on August 24, 2014 in West Hollywood, California

Sims, who also appeared in this summer’s “Dawn of the Planet of the Apes,” is a UCLA Theater grad who started booking jobs soon after graduation – including TV roles in ABC’s 2003 series “10-8,” Starz’s first original series “Crash,” FX’s critically-acclaimed drama “The Shield” and CBS’ top-rated “NCIS.”

Below, he tells us how his Hollywood grind was able to generate gig after gig so quickly:

“Masters of Sex” airs Sundays at 9 p.m on Showtime. Watch a promo for Sunday’s (Sept. 14) episode “Below the Belt” below: