S4 E1 · Freefall
Masters is caught drunk-driving and Johnson works with Hugh Hefner.
All episodes for series 4 of Masters of Sex
S4 E2 · Inventory
Masters and Johnson focus on their expanding clinic.
S4 E3 · The Pleasure Protocol
Masters and Johnson adjust to new partners.
S4 E4 · Coats or Keys
Johnson, Masters, Libby, Betty, Lester and Keller wind up together at a swingers party.
S4 E5 · Outliners
Masters is forced to make a difficult admission.
S4 E6 · Family Only
Johnson tries to get her relationship with Bill back on track.
S4 E7 · In to Me You See
Masters intends to make Art his protege as he expands his research.
S4 E8 · Topeka
Masters and Johnson go on the road and pose as a couple at a competing clinic.
S4 E9 · Night and Day
Masters and Johnson must deal with the ramifications of their trip to Topeka.
S4 E10 · A Private Affair
As the practice disintegrates, Masters and Johnson make an important choice about their future.
