‘Masters Of Sex’ Season 4 Spoilers: Showtime Show Adds Kelli O’Hara As Bill Masters’ Ex-Lover

"Masters Of Sex" is keen to explore not only Bill Masters' (Michael Sheen) future, but also his controversial past. Viewers have seen Virginia Johnson (Lizzy Caplan) romance a slew of lovers, most notably the brash young resident Dr. Ethan Haas (Nicholas D'Agosto) and, most recently, perfumer Dan Logan (Josh Charles). Now, fans will see Bill interacting with his past lover.

Tony award-winning actress Kelli O'Hara has been cast in season 4 as Dody, a long-lost love of Michael Sheen's character, TVLine reports. O'Hara's character will appear in multiple episodes of the upcoming season. She will first appear on the Showtime series in order to clear the air about her sudden departure from Bill's life several years ago.

Interestingly, "Masters Of Sex" has another Broadway actress in its cast. Apart from the recently recruited Kelli O'Hara, Annaleigh Ashford, who plays the colorful character of Betty Dimello, is also a Tony award-winner. Looks like this drama series is keen on tapping the best actors in the industry.

RELATED: Virginia Johnson Marries Dan Logan?

Season 4 will begin with Masters and Johnson reviving their practice as their personal lives come crashing down. Bill is left to deal with the legal repercussions of his lawsuit and prostitution chargers, whereas an unhappily married Virginia is seen bedding a stranger in the trailer.

Watch it below:

Several new actors have been added to the Showtime drama in season 4. David Walton joins the TV show as a high-powered attorney who represents Masters in his legal battles, Niecy Nash joins the stellar cast as an Alcoholics Anonymous member and Betty Gilpin joins Masters and Johnsons' practice as a new doctor. Erin Karpluk has also been tapped to play a new patient.

"Masters Of Sex" season 4 premieres on Sunday, Sept. 11, at 10 p.m. EST on Showtime.