Steven Soderbergh's latest film—and if he is to be believed, his last—confounds expectations with outstanding panache.

It's reasonably common for studios to request that critics take special care not to reveal the secrets of a particular film. It's rather less common that such a film has secrets worth keeping.

Side Effects, the new movie from cinematic polymorph Steven Soderbergh, is a happy exception, a crafty teaser that presents itself as one kind of film before gradually evolving into another kind altogether. I, for one, enjoyed both enormously. For readers who are devout fans of Soderbergh, or otherwise already intend to see Side Effects, my advice is this: Stop reading now, avoiding learning anything more about the film than you already know, and see it at your earliest convenience. For those who are on the fence, read on. I promise to give away as little as I can manage.

Related Story

How Steven Soderbergh Made Channing Tatum Into Hollywood's Most Capable Lunk

The film opens with a crime scene in a New York apartment: a chair is overturned and the bloody prints of bare feet traverse the floor. A model sailboat—evidently a gift—sits in mute witness to whatever violence has taken place.

Cut to three months earlier. Emily Taylor (Rooney Mara) is putting on lipstick to welcome home her husband, Martin (Channing Tatum), following his prison stint for insider trading. Their reintegration is bumpy: Martin fails in the conjugal act and talks enthusiastically about a guy he met on the inside with "money in Dubai and a lot of connections"; Emily listens to his new schemes with palpably escalating anxiety. Before long, she is accelerating her sedan into the concrete wall of a parking garage.

Emily awakes to find herself in the care of Dr. Jonathan Banks (Jude Law). This is not, we learn, her first bout of severe depression. Before Martin went to prison she had been in the care of another psychiatrist, Victoria Siebert (Catherine Zeta-Jones). So assessments are made and drug treatments considered, some real (Zoloft, Effexor, Wellbutrin), others invented (Ablixa, Delatrix).

What unfolds over the film's first half is perhaps cinema's first pharmacological thriller, one in which the crime and offender are known, but guilt an open question. Is the perpetrator responsible, or is a drug—and if the latter, who's to blame? The prescribing doctor? The pharmaceutical company? Free will grapples inconclusively with chemical determinism, and for a time it seems that Side Effects will be, like Soderbergh's earlier Contagion, an epidemic film—though in this case the story of the afflictions we've brought upon ourselves in our quest for the perfect pill.

What unfolds over the film's first half is perhaps cinema's first pharmacological thriller, one in which the crime and offender are known, but guilt an open question.

But, as noted, Soderbergh has other plans in store. The script, by Scott Z. Burns (Contagion, The Informant!), will flip, and flip again. Victims will become victimizers; puppeteers, puppets; defenders, accusers. Questions of sanity and obsession will be raised and then reversed. (Echoes of Rear Window and Vertigo ring loudly.)

There are some, no doubt, who will be disappointed by the film's cultivated confounding of expectations, and perhaps not without reason. The questions Side Effects raises early are genuine ones, and it ultimately evades them, opting for entertainment over moral exploration. But with a few exceptions—an unnecessary gust of same-sex steam in particular—the movie's evasions are diabolically sharp. (There are echoes, too, of Soderbergh's early effort The Underneath.) The cast is uniformly strong, with Law and Mara particular standouts; Burns's script has more twists than Lombard Street; and Soderbergh navigates with exquisite control.

Will this be the director's last film, as he continues to claim? I confess that I can't conceive it, even with the outs he has granted himself to experiment in theater and on television. Soderbergh has directed more than two dozen movies in as many years (and almost as many genres), from Sex, Lies and Videotape to the Ocean's movies, from Bubble and The Girlfriend Experience to Erin Brockovich and Traffic, from Che to Solaris to (my own favorite) Out of Sight. I fully expect him to be back, perhaps before long. But if he's not, if Side Effects is truly Soderbergh's big-screen finale, it is not only worthy, but characteristically original.