When it comes to eco-living, Rebecca Hall does "everything I can. I organize my trash. I don't drive. I take public transport and I ride a bicycle. I walk a lot," says the British actress ("Vicky Christina Barcelona," "The Town"), who stars opposite Benedict Cumberbatch in the five-part miniseries "Parade's End," premiering Feb. 26 on HBO.

Beginning in 1912, shot in the U.K. and Belgium and adapted by Tom Stoppard from Ford Madox Ford's novels, the story follows a Conservative aristocrat (Benedict Cumberbatch), married to a cheating wife (Hall), who falls in love with a young suffragette (Adelaide Clemens).

Hall's Sylvia is selfish, cruel and manipulative but still evokes sympathy, and those contradictions attracted the star. "It's rare when you come across a character that is capable of such tremendous and glorious acts of sadism, yet at the same time is somehow endearing," she says. "She is, in many ways a modern woman. She's slightly before her time. She's very emotionally intelligent, very able, but she has no education and no career, and all of that resource sort of goes untapped, as it were," Hall observes. "She has no analytic capability, so it goes into manipulation and generally turning into a demon. If she had something else to do, she probably wouldn't be quite as sadistic. It's boredom, and the injustice of not being able to lead an autonomous life on the same footing as a man."

Wearing a different outfit in every scene, Hall says she "learned a lot about glamour" in playing the role, and she relished the miniseries format. "You're allowed to play the extremes much more unashamedly when you know you've got five hours to do it. If somebody doesn't hate Sylvia by the end of episode one I'm not doing my job. And equally, if somebody doesn't love Sylvia by the end of episode four I'm not doing my job. I knew I had to commit 100 percent playing the demonic empire as well as the angel. I've never been able to do that in two hours. You just don't have the time for that kind of detail."

Audiences will be seeing a lot of Hall this year, in a French film called "A Promise;" in "Closed Circuit," in which she and Eric Bana play lawyers — and ex-lovers — who are put in danger when they defend an international terrorist; and "Iron Man 3," due out May 3. Although she can't discuss the plot, she says "it was a fantastic experience. It's a commercial movie but it has great wit and intelligence."

Photo: Nick Briggs/HBO

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