MASTERS OF SEX stars Michael Sheen and Lizzy Caplan, who portray the real-life pioneers of the science of human sexuality, William Masters and Virginia Johnson. The series chronicles the unusual lives, romance and pop culture trajectory of Masters and Johnson. Their research touched off the sexual revolution and took them from a mid-western teaching hospital in St. Louis to the cover of Time magazine. Masters and Johnson work to save the practice from disintegrating in the face of insurrection within the clinic. As everyone in their lives either moves on or falls away, Bill and Virginia find solace in one another. Season finale. Masters and Johnson return from Topeka, each grappling with the trip's ramifications. Art and Nancy look to tie up loose ends in order to have a fresh start, and Libby embarks on a road trip with Bram that changes her perspective. Masters and Johnson go on the road and pose as a couple to investigate practices at a competing clinic. While Bill and Virginia are away, Art, Nancy and Langham take advantage of their absence to further their own agendas. Masters looks to groom Art as his protege in a new area of research as Johnson does her best to keep Nancy at arm's length. Betty seeks an unlikely source for assistance in her fight for equal rights to Helen's baby. Johnson looks to get her relationship with Masters back on track while Masters does his best to find satisfaction elsewhere. Betty and Helen ready themselves for a new addition; Art and Nancy discuss the consequences of their party.