The trailer for the new Showtime series Masters of Sex, debuting after Homeland this Sunday night at 10pm. It's based on the 2009 biography of Masters and Johnson, the most famous sex researchers in American history next to Alfred Kinsey, whose studies in the 1950's and 60's recorded some of the first laboratory data on the anatomy of the human sexual response. Starring Michael Sheen and Lizzy Caplan in the lead roles, the show's getting some pretty good reviews so far and could be a new hit of the fall season.