In the wake of their fallout, Masters and Johnson search for purpose, 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 answers in unexpected allies.

Masters and Johnson turn to new partners in an effort to put the past behind them and focus on their expanding clinic. Libby evaluates her relationship with Bill and Virginia given their fractured triangle.

Masters (Michael Sheen) and Johnson (Lizzy Caplan) begin working independently, unaware that their new associates are a couple. Libby (Caitlin Fitzgerald) is asked to be a character witness at Masters' upcoming criminal trial.

Johnson (Lizzy Caplan) accepts Nancy (Betty Gilpin) and Art's invitation to a party at their home, unaware of the sexual surprises in store. Libby's (Caitlin Fitzgerald) sexual demands create an opportunity to reconcile with Masters (Michael Sheen).

Johnson (Lizzy Caplan) heads to New York as her and Masters' (Michael Sheen) criminal trial begins. Art and Nancy (Betty Gilpin) discover they are being recorded, Betty (Annaleigh Ashford) presses Helen to tell her parents about their relationship.

As Johnson (Lizzy Caplan) and Nancy (Betty Gilpin) compete for attention from Masters (Michael Sheen), and Libby (Caitlin Fitzgerald) admits that she's dating again, Helen goes into labor.

After agreeing to a new working arrangement, Johnson (Lizzy Caplan) presses Masters (Michael Sheen) to expose the shoddy sex clinics that are springing up around the country. Betty (Annaleigh Ashford) devises a plan to get custody of her daughter.

As Masters (Michael Sheen) reconnects with a long-lost lover while he and Johnson (Lizzy Caplan) investigate their competition, Nancy (Betty Gilpin) takes advantage of their absence to propose that she and Art start their own clinic.

As her parents' visit to St. Louis brings many surprises for Johnson (Lizzy Caplan), Nancy (Betty Gilpin) and Guy face obstacles to starting their own practice.

With the wedding plans being threatened as things unravel at home and work, a visitor from Masters' (Michael Sheen) past reemerges.