Caitlin Fitzgerald
Caitlin Fitzgerald dished details on her "Masters Of Sex" Season 4 character Libby. Eric Charbonneau/AP Invision for SHOWTIME

“Masters Of Sex” Season 4 will be very different from Season 3. The Season 3 finale saw Bill’s wife Libby finally confess to him that she knew he was having an affair with his fellow researcher Virginia for several years. Bill was visibly shocked. The Showtime drama also depicted Bill’s love life and practice collapse in 2015. The drama’s third season was more or less serious since the doctor’s downfall was shown.

However, Caitlin Fitzgerald, who plays Libby on “Masters Of Sex,” assured TVLine that Season 4 will be a lot lighter and funnier. Now that the series is steering towards the swinging 60s and early 70s, with people enjoying the sexual revolution, it’s clear that Bill’s story will take on a sunnier outlook.

Fitzgerald also revealed, “I haven’t cried one time. I barely recognize this [Libby’s] character!” as evidence that Season 4 will certainly be low on the melodrama and high on humor. Libby has been prone to emotional outbursts in previous seasons since she has been struggling to keep her family intact. Marital problems, issues with her pregnancy and Bill’s (Michael Sheen) legal woes have understandably shown her as a depressed housewife.

However, Fitzgerald shared that the long-suffering Mrs. Masters will experience a lot of righteous anger once “Masters Of Sex” Season 4 kicks off. She will also share her bed with multiple partners, most notably Bill’s attorney, whose character is played by David Walton.

The Showtime series will also see Bill and Virginia Johnson (Lizzy Caplan) rebuilt their burned bridges after their personal and professional lives collapsed. Despite Dan’s (Josh Charles) proposal, Virginia will not marry him. She will focus on her sex research and aim at rebuilding the practice.

“Masters Of Sex” Season 4, episode 1, titled “Freefall,” premieres on Sunday, Sept. 11, at 10 p.m. EST on Showtime.