The movie holds all kinds of feints and decoys, but its biggest surprise is Mara. After her mannered, vacant performance in the American version of The Girl With the Dragon Tattoo, people like me wondered: Why is she in movies? The answer: To make this one. Caressed by golden hues in the sunny flashbacks, appearing wan and frail in some of Emily’s darker moments, Mara proves worthy of Soderbergh’s closeup attention. Emily may not always be reliable; her descriptions of her symptoms — “Every afternoon at three, there’s this poisonous fog bank, rolling in on my mind” — have the whiff of a borrowed epigram (William Styron’s, from Darkness Visible). But, surrounded by some of Soderbergh’s favorite actors, Mara makes her peculiarly watchable; viewers scan her face for clues to a woman as elusive as she is smart.