Picture a woman mechanically cutting tomatoes with a sharp knife. She’s smiling until a man walks in, and the woman’s facial expression becomes suddenly devoid of all emotion. She turns slowly and then stabs the man repeatedly. She stares at him unapologetically as he falls and begs for help. Once he is silent, she walks past his body into her bedroom, gets under the covers and falls asleep.

It’s a scene that serves as the crux of Stephen Soderbergh’s new and purportedly final film, “Side Effects.” Starring Rooney Mara as Emily, a woman who becomes depressed when her husband Martin (Channing Tatum) returns from prison, the film revolves around the couple’s increasingly tumultuous relationship. After attempting suicide, Emily is introduced to psychologist Dr. Banks (Jude Law), who prescribes her a medication called Ablixa. Matters seem to be improving until one day Emily stabs her husband. With no recollection of the incident, Emily is arrested and admitted to a mental institution ­— the question of what happened that night and who is truly to blame still lingers.

This intriguing plot is easily the film’s most powerful component. The screenplay, written by Scott Z. Burns, is unique, leaving the audience unsure of the full truth until the very end. The deception is intricate and carefully planned to the last detail.

Unfortunately, the plot is just about the only unconventional part of the film. Rather than focusing on a female protagonist, “Effects” dotes on its male lead, Dr. Banks, as he tries to uncover the truth. The audience only catches brief and incomplete glimpses of Emily’s story. “Effects” also makes the predictable choice to portray Emily as an unsatisfied wife ­— like a recycled “Desperate Housewives” character.

Law’s performance as Dr. Banks is often tiresome. His character is sexist, caring little about the origin of Emily’s depression or her feelings. Still, Law does an effective job at playing an intense role, allowing the desperation to shine through and reveal a seemingly demented man who will stop at nothing to return to normalcy. Mara also shines, particularly once her character’s shell begins to crack, revealing a much more complex character than expected. She does a terrific job at portraying seemingly contradictory personalities.

This is said to be the last film Soderbergh will direct. Known for making films in a myriad of genres, Soderbergh gives “Effects” the pacing of a classic thriller, and the strong performances and sustained suspenseful tone make the film an entertaining finale for the director. Despite the film’s slightly sexist insistence on focusing on the male lead, those who enjoy crime, thriller and suspense films will enjoy what “Side Effects” has to offer.

Katherine Tejeda is a contributing writer. Email her at [email protected].