Side Effects Ending, Explained: Why Did Emily Kill Martin?

Directed by Steven Soderbergh and based on a script by Scott Z. Burns, ‘Side Effects’ (2013) is a psychological thriller film. It revolves around Dr. Jonathan Banks (Jude Law), a psychiatrist whose career is on an upward trajectory, with partnership in a thriving practice and involvement in drug studies. Jonathan also regularly works with law enforcement. He encounters Emily Taylor (Rooney Mara), a young woman who tried to die by suicide. Emily claims that she has depression, prompting Jonathan to prescribe her certain drug at the suggestion of her former psychiatrist, Victoria Siebert (Catherine Zeta-Jones).

When Emily kills her husband Martin (Channing Tatum), she claims she did it while sleepwalking, a side effect of the drug mentioned above. As this ruins Jonathan’s career and personal life, he desperately tries to find a way to prove his innocence. Did Emily get what she deserved in Side Effects? SPOILERS AHEAD.

Side Effects Plot Synopsis

The film opens with a shot of bloodstained footmarks on the floor before the camera focuses on what looks like gifts. The narrative then shifts three months back. Emily goes to meet Martin in jail. He has been doing time for inside trading but is about to be released. By all indications, they look like a loving, happy couple. Emily is a Bedford, New York, socialite. Before Martin’s incarceration, she had an active life in one of the upper tiers of the city’s social life. But as it often happens in such cases, the friends she and Martin used to have, even the ones who were just as guilty, have developed tactics to ignore them politely.

On the day Martin is supposed to be released, Emily speaks to her boss, reminding the other woman that she applied for a day off before going to the prison along with her mother-in-law to pick Martin up. That evening, after they make love, Martin promises her that he will do everything he can to get them back on track. He even mentions meeting a hedge fund manager in jail. The man has promised Martin a partnership once he (Martin) gets out.

Emily seems to be suffering from severe depression. One evening, after she is done with her work. She drives her car straight into a wall. She survives with some bruises, especially after the parking attendant present there calls the emergency services. This is how she enters into Jonathan’s life. Jonathan speaks to her at the hospital and agrees to be her psychiatrist after she declines to stay for a few days.

However, what Jonathan prescribes to Emily for her depression doesn’t seem to work. After learning about Victoria from Emily, he goes to speak to her. Emily had sessions with Victoria while she was still living in suburbia in Connecticut. Victoria reveals that Emily had a miscarriage after her husband’s arrest and suggests that Jonathan should give Emily a new drug called Ablixa.

Meanwhile, Emily tries to take her own life again — this time by attempting to fall in front of an oncoming subway train. But a police officer present at the station seemingly pulls her back in time. Afterward, she rushes to meet Jonathan, who is speaking to his wife, Deidre, at the time and tells him what has happened. She brings up Ablixa, claiming that her friend from work, Julia, uses them and has gotten positive results. This prompts Jonathan to finally prescribe her the medicine.

Things seemingly get better after that. But one downside of the medicine seems to be sleepwalking, which is indeed listed among Ablixa’s side effects. After watching Emily roam around their apartment and set the table as if they will have multiple guests, a concerned Martin accompanies her to Jonathan’s office. When he asks Jonathan if they can change the medicine, Emily vehemently refutes the notion, claiming that this is the best she has felt in a long time. As a compromise, Martin writes her several other drugs that can suppress that side effect.

However, Martin comes home one evening and realizes that Emily is sleepwalking again. When he tries to wake her up, she stabs him multiple times with the kitchen knife she has been using. As Martin dies on the floor, Emily goes to sleep.

After the authorities are informed, they contact Jonathan because Emily has asked for him before any lawyer. The prosecutor demands Jonathan’s help with the case. Jonathan deduces that Emily killed Martin while sleepwalking. Despite the warning he has received from the prosecutor, Jonathan resolves to fight for Emily, effectively putting his career in jeopardy. As things stand now, Martin’s death was either a premeditated murder, or it happened because of the drug Jonathan prescribed. Emily pleads not guilty by reason of insanity, and the presiding judge in her case gives an innocent verdict and sends her to a psychiatric facility, where Emily has to stay under Jonathan’s supervision until the latter clears her.

Side Effects Ending: Why Did Emily Kill Martin? Why Did Victoria Siebert Help?

In ‘Side Effects,’ it is pretty much established that Emily killed Martin. The real question is why she did it. As Jonathan decides to support Emily, his partners throw him out of the practice, and the drug company that earlier agreed to work with him cancels the deal. But Jonathan learns one key piece of information from their representative. After what happened with Emily, Ablixa’s stocks took a sharp dive, and people who shorted it made an exorbitant amount of money.

Given Martin’s past, Jonathan gets the inclination that Emily made money because of the sharp fall of the value of Ablixa’s stocks. Realizing that he has become a mere pawn in a larger game, Jonathan tries to take control of the situation by tricking Emily into believing that he has injected her with truth serum. He tells her that the side effect of this drug is drowsiness. When Emily acts sleepy even though he has injected her with only saline water, Jonathan gets his proof by recording Emily.

However, when Jonathan goes to the prosecutor with the video, the latter refuses to do anything, pointing out to Jonathan that he will be arrested and lose whatever reputation he has left if the video he made ever gets out. When Jonathan confronts Victoria, the latter sends doctored photos of Jonathan and Emily to Deidre, which leads to Deidre leaving Jonathan and taking their son with her.

Eventually, Jonathan uses paranoia of these two women against them. He tells Victoria that Emily told him everything and tells Emily that he and Victoria are working together. Emily confesses that she seduced Victoria, and they helped each other. Victoria helped her with her knowledge of the drugs, while Emily helped Victoria with what she learned about stocks from Martin.

Emily killed Martin because the downward spiral in her life started after his arrest. She had gotten everything she had ever wanted after marrying Martin. But she also lost everything because of him. As she tells Jonathan, killing Martin was not a decision she made just once; she made it over and over again every time she looked at her life and saw the position she was in and who put her there.

Why Did Emily and Victoria Target Jonathan?

It turns out that Emily and Victoria targeted Jonathan completely by chance. Anyone with a pad could have approached Emily after her first apparent suicide attempt, and she and Victoria would have focused on them. Jonathan was supposed to go away after the trial. Things became complicated when he didn’t.

Emily never really took any other drug, and Ablixa had no effect on her. She faked the suicide attempts, ensuring there were people who noticed her in both cases. Emily agrees to work with the authorities against Victoria, helping Jonathan to bring the psychiatrist down by wearing a wire.

If Emily was hoping that Jonathan would let go after that, she was grossly mistaken. Jonathan, who still serves as Emily’s case psychiatrist, sends her back to the psychiatric facility after she refuses to take Thorazine and Depakote. Because of double jeopardy, Emily can’t be charged with murder, but she still will spend years institutionalized. As the film ends, we see Jonathan with his wife and son. The implication here is that he and his wife have reconciled.

Read More: Where Was Side Effects Filmed?