Here it comes: the next U.S. cable drama to natter about, argue over and consume, bit by delicious bit. What's it about? Simply put: Sex. But not salacious sex, depending on your point of view, anyway. Certainly not sex as the episode-ending climax to some raw, torrid encounter between characters, as the music rises and then the credits consume the screen.

The series is Masters of Sex, made by Showtime (airing in Canada on TMN/Movie Central) and starting Sept. 29. It's about the real lives and careers of William Masters and Virginia Johnson, whose vanguard research into sexual arousal and disorders led to two classic, era-changing books: Human Sexual Response in 1966 and Human Sexual Inadequacy in 1970. Both scholars became celebrities because they upended conventional thinking on desire, bodily response and orgasm.

The 12-part series, achingly lovely and anchored in so much sexual angst, is based on a 2009 book, Masters of Sex, written by Thomas Maier. John Madden, who made Shakespeare in Love and The Best Exotic Marigold Hotel, directs some episodes and is also a producer.

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This is about the study of sex, desire and satisfaction. And although there's science involved, it's about real people and it's a good bet that Masters (played by Michael Sheen) will stride into centremost point of the conversation where the trends and tensions of the culture are brooded upon.

The Masters character, in fact, might follow in the cable-drama footsteps of Tony Soprano, Don Draper and Walter White. All of them are burdened, problematic men: In this case, Masters is a man with serious issues of control, ego and awkwardness with women, yet he will, eventually and ironically, propel women's liberation and the sexual revolution forward. Tricky guy to like and understand, that Bill Masters.

Sheen thinks any Soprano-Draper comparison is flattering, but says he's wary of too much advance praise. And doing press interviews about the show has been an odd experience. "Most of the questions I get asked amount to: 'What is the most surprising thing you learned about sex from this project?'" he says. "That's pretty much the agenda people have. Not everyone is comfortable talking about the material in Masters of Sex."

The Welsh-born actor, best known here for his award-winning roles as British Prime Minister Tony Blair in The Queen and as TV interviewer David Frost in Frost/Nixon, is pleased to talk at some length about his character and the series. He's relaxing on a couch outside a room where he'd just done some TV interviews, and the sound-bite quality of it all – talking to people who haven't even seen series yet – is something he wants to leave behind.

"There are an awful lot of complications with Bill Masters," he says. "The thing that shocked me was that this man, who did so much to advance the role of women and in liberating women from restraining myths about sexuality, was such a man of his time – an alpha male, a misogynist, really, who became this accidental hero of the women's movement. Very strange."

As told in the series, Masters was a successful gynecologist and fertility expert at Washington University in St. Louis in the mid-1950s. (Masters died in 2001; Johnson died in July at the age of 88.) But even while he led his field, he was carrying out secret research – he persuaded a local brothel owner to allow him to spy on prostitutes and customers having sex in order to discover the secrets of arousal and orgasm. He took notes, timed the length of the encounters, interviewed the prostitutes. There is a touch of the Mad Men-era about these scenes – the stiff 1950s society, the successful man with a secret interest in taboo subjects, the condescension toward women.

In the series, it takes Masters a long time to get funding and approval for real laboratory research into sexual appetites and needs. We see his boss in a rage, describing the study as "smut." At that time, only Alfred Kinsey had published scientific material on sexual behaviour, and much of it was based on interviews as opposed to obervation. Masters wanted rigorous, laboratory-based research. He wanted to see people have sex, monitor their bodily reactions, and measure everything from arousal to orgasm.

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Undertaking that research at last, Masters hires Johnson (wonderfully played by Lizzy Caplan) as a research assistant. An unusual woman, she's frank about her sexual history and needs, and thus an immensely illuminating figure for Masters. (There's a stunning scene in which another doctor screams and hits her for her candid attitude about sex.) Meanwhile Masters is married, his wife cannot conceive and he's hiding something profound about his own sexual history.

The main dramatic shift in Masters of Sex occurs when laboratory work is under way, when Masters and Johnson observe real subjects engaging in sex. The subjects are wired to monitor every possible reaction. The sex scenes fall into an unknown category, somewhere between porn and science project. Some viewers will find it unnerving.

Sheen says that managing the scenes, for actors and audience, is all about tone. "It really is a very new kind of show, I think, in terms of the subject matter," he says. "Real people, real events, with so much sexuality on display – it has to be absolutely believable. It's also going between images and scenes with nudity and sexuality that would be seen, I suppose in conventional terms, as sexually exciting. But it's up against things that are much more medical and gynecological, and notoriously, we as a culture and a society have some issues with that kind of thing. Finding a cohesive whole that doesn't alienate the audience is tough.

"We discovered the tone through experimentation, through actually making it," he adds. "Eventually, it starts to cohere. There's a question about the humour as well, that it has to come out of the situation."

True, there is humour, sometimes dark. But Masters of Sex is really, and compellingly, about Bill Masters and Virginia Johnson, two scientific pioneers leading a cultural revolution in a laboratory. Their work on female orgasm changed how women see themselves and how the world now sees women's sexuality. And then there's just Bill and Virginia, two maddening, complex people on a journey as much about their feelings for each other as it is about the anonymous couples having sex in a lab. Sometimes you will want to look away from it all, but you can't.