The fourth season of Masters of Sex began airing in the United States on September 11, 2016. The series is the television adaptation of Thomas Maier's biography Masters of Sex: The Life and Times of William Masters and Virginia Johnson, the Couple Who Taught America How to Love. It stars Michael Sheen as Dr. William Masters and Lizzy Caplan as Virginia Johnson.
The fourth season takes place in 1968 and 1969.
A month after their fallout, Bill's life is in shambles. After getting into a car accident, he is forced to go through AA meetings, where he meets Louise, who encourages him to keep going to the meetings even though he's not an alcoholic. Meanwhile, Virginia is in Las Vegas, after getting into an ugly breakup with Dan. She is anxious to capitalize on her fame, and wants Hugh Hefner to publish an article in his magazine. Hefner agrees, but will only invest in the business if Bill and Virginia continue to work together. Bill and Virginia agree to work together as long as the work stays strictly professional--and want to bring in new partners for the both of them.
Bill starts by hiring Nancy Leveau, a former associate of Barton's. Virginia retaliates by hiring Art Dreesen, a psychologist. Virginia soon finds out that Nancy and Art are married and in an open marriage. After a night at a swingers party lands Art and Virginia together, Virginia finally confronts her feelings towards Bill--and realizes she still loves him.
Meanwhile, Libby and Bill plan on having a divorce, after Bill revealed he has been having an affair at the end of the previous season. However, their relationship softens throughout the season. Because of their legal issues, Bill's lawyer, Bram Keller, tries to get Libby to not pursue the divorce until after the trial ends. Libby and Keller go on to develop a close, intimate relationship. Libby gets an offer to study law in California, where she moves at the end of the season.
Things get heated between Virginia and Nancy. Virginia wants Nancy and Art fired, especially as she learns Art told Nancy that he and Virginia had sex--which they did not. Bill allows the two of them to stay on. Nancy wants to start her own clinic with Art. However, after Art learns that Nancy aborted his child, he wants nothing to do with her and turns her in to Bill and Virginia.
Virginia continues to try and pursue Bill, who is reluctant to get back involved because he doesn't want to be hurt again. After going undercover to investigate a competing clinic in Kansas, Virginia reveals that she loves him, and he says he loves her too. The two, reunited at last, agree to get married. Even though Virginia's parents marriage is falling apart and Bill's family is moving away that day, Bill and Virginia finally get married, and are photographed by the press exiting city hall, husband and wife.
|Picture||#||No.||Title||Original Air Date|
|37||1||Freefall||September 11, 2016|
|In the wake of their fallout, Masters and Johnson search for purpose in a world without one another and look to work as their personal lives crash down around them. Libby finds herself alone for the first time since her marriage and discovers some unexpected allies.|
|38||2||Inventory||September 18, 2016|
|Masters and Johnson turn to new partners in an effort to put the past behind them and focus on their expanding clinic. Given their fractured triangle, Libby reevaluates her relationship with Bill and Virginia.|
|39||3||The Pleasure Protocol||September 25, 2016|
|Masters and Johnson adjust to new partners, but their respective cases have them second-guessing the instinct to remain separated. A romantic prospect pushes Libby to embrace life as a newly single woman of the sexual revolution.|
|40||4||Coats or Keys||October 2, 2016|
|Bill, Virginia, Libby, Betty, Lester, and Keller all end up at a swingers party hosted by Art and Nancy; Bill and Libby re-examine their complicated relationship; Virginia confronts her feelings toward Bill.|
|41||5||Outliers||October 9, 2016|
|With their legal troubles coming to a resolution, Bill is forced to make a difficult admission, while considering reuniting with Libby; Virginia goes to New York to salvage their book deal.|
|42||6||Family Only||October 16, 2016|
|Virginia deals with insubordination in the clinic, and continues to try to reunite with Bill, despite his pulling away; Helen goes into labor and Betty is left dealing with the aftermath of her in-laws abrupt exit and an unforeseen tragedy.|
|43||7||In To Me You See||October 23, 2016|
|Bill contacts a lover from his past, while he and Art try to help a possibly bisexual client continue with his marriage; Virginia and Nancy discover their clinic is under scrutiny from competing businesses; Louise from AA surprises Bill, in need of a favor.|
|44||8||Topeka||October 30, 2016|
|While investigating a competing clinic in Topeka, Virginia is horrified to learn that Bill and a former lover have met in person; Austin comes upon a new business venture.|
|45||9||Night and Day||November 6, 2016|
|Virginia is dismayed to hear that her parents marriage is on the rocks; Bill learns that Louise has fallen off the wagon; Libby and Bram get stuck in a traffic jam.|
|46||10||The Eyes of God||November 13, 2016|
|Bill and Virginia plan their wedding, while taking precautions as they learn Nancy is planning on opening her own clinic; Libby plans on moving to California to study Law at Berkeley.|