Among the darker pleasures of moviegoing is the spectacle of men and women enacting scenarios that link illicit sex and less-than-accidental death, sensational events few of us have experienced but for which we may, perhaps, secretly hunger. Restrictions on what could be shown or spoken yielded decades of film classics in which we read between the lines. But once those cinematic taboos were broken, filmmakers actively pushed the censorship envelope, dared actors to disrobe and dissemble, and held up a mirror to audiences’ changing mores. By the 1990s, the erotic thriller was a genre and a cottage industry unto itself. In looking forward to the Valentine’s Day release of François Ozon’s delirious psychosexual mystery Double Lover, the Quad turns up the heat with a torrent of risky couplings, deadly obsessions, bad girls, worse guys, head games, criminal acts, and bodies either heading for each other or heading for the morgue.