In the last 18 months, Steven Soderbergh has cranked out films with stunning efficiency, bouncing around genres with “Contagion,” “Haywire,” “Magic Mike,” and finally, “Side Effects,” a worthwhile dip into the pool of the psychological thriller. Soderbergh has threatened to retire after “Side Effects,” but the riveting, surprising thriller proves that his voice is as strong as ever.

Emily Taylor (Rooney Mara), a mentally bruised woman, begins to spiral after her husband Martin (Channing Tatum) is released from prison. Psychiatrist Jonathan Banks (Jude Law), worried about Emily, prescribes her a rotating regimen of antidepressants. As Emily struggles to get back on her feet, her new meds cause more trouble than they’re worth, with dangerous results for the people in her life.

Screenwriter Scott Z. Burns has collaborated with Soderbergh before on “The Informant!” and “Contagion,” and he stages a twisty, engaging shell game. “Side Effects” overflows with clever dialogue and creates fascinating characters. As the film dives into its plot (the particulars of which are best left unspoiled), the dynamic between Emily and Dr. Banks becomes increasingly layered and unpredictable. However, “Side Effects” suffers from a few storytelling problems, and its final stretch gives into unexpected pulpy instincts a bit too readily, resulting in a convoluted conclusion that reveals very little about the characters or story.

However, director Steven Soderbergh presents “Side Effects” with such unflappable confidence that even when the story is stretched thin, his aesthetic moves things along so smoothly that it’s hard to notice. Soderbergh works with remarkable economy in every frame, keeping his images perfectly sparse. His best work is in the film’s first movement, as he roots the audience firmly in Emily’s perspective by placing her as the only object in focus, while the world around her is blurry and hard to maneuver. It’s evocative, smart direction, and another reason why Soderbergh is one of the most perceptive directors working today.

Rooney Mara surprised everyone with her fearless performance in “The Girl With the Dragon Tattoo,” and she continues to impress here. As the side effects of Emily’s medication become increasingly troublesome, Mara gracefully skips between charming, dreamy, and icy. Jude Law brings plenty of acumen and determination to Dr. Banks, making him an easy anchor for audience sympathy in the murky waters of the film’s second half.

“Side Effects” starts to falter a bit as things wrap up, but Steven Soderbergh’s assured direction and wry performances from Law and Mara keep things afloat. Soderbergh certainly works enough to have earned his retirement, but his clear, engaging voice and unshakable confidence pair so well with Scott Z. Burns’ strong character work and shining dialogue that it’s hard not to wish for more collaborations between the pair.