OSTENSIBLY STEVEN SODERBERGH'S final film to be released in theaters—his final final film, the Liberace flick Behind the Candelabra, with Michael Douglas and Matt Damon, is headed straight to HBO—Side Effects doesn't have the weight one would expect. Then again, most of Side Effects isn't what people are expecting. Thanks to cagey advertising, audiences will be in for a surprise as Side Effects unfolds: What starts as an intensely accurate study of a young woman's depression gradually contorts itself into something else entirely. Soderbergh's calculated eye, paired with Scott Z. Burns' script (the pair recently worked together on the excellent thriller Contagion, a film guaranteed to give you hypochondria), finds plenty to grab onto in the story of 28-year-old graphic designer Emily (Rooney Mara). Even as her husband (Channing Tatum) rejoins her after his four-year prison stint for insider trading, Emily struggles with crippling hopelessness—a weary, bone-deep sadness. After a jarring suicide attempt, Dr. Jonathan Banks (Jude Law) starts Emily on Ablixa, a new, unproven antidepressant, at which point things get even more intense. Side Effects begins in a place too many of us know entirely too well, then grows pulpier and pulpier: In interviews, Soderbergh's said films like Fatal Attraction influenced Side Effects, but it also resembles the long-extinct erotic thrillers of the '90s.

That's not to say Side Effects isn't good, though, because it is. (And so was Poison Ivy, if my memories of watching it, wide-eyed at age 12, are reliable.) Anchored by strong performances and Soderbergh's relentlessly efficient storytelling, Side Effects never stops being engaging and entertaining, even as it sways between genres, even as blood starts to flow, and even as it's bumped around by a steady stream of revelations. Soderbergh's best work? Nope. But it's a totally enjoyable, deceptively nuanced trip into the parts of the brain we still don't understand—and, all things said, not a bad way for Soderbergh to exit the multiplex.