Who Killed Adam in 'The Better Sister'? Spoilers Ahead

Warning: This article contains spoilers Prime Video’s The Better Sister

Jessica Biel and Elizabeth Banks’ twisty whodunnit, The Better Sister, has arrived on Prime Video and there is one main question gripping viewers from the first episode until the last: Who killed Adam?

The show, which is based on Alafair Burke’s 2019 novel of the same name, follows high-profile media executive Chloe (Biel) who married her brother-in-law Adam (Corey Stoll) and began raising her estranged older sister’s son Ethan (Maxwell Acee Donovan). When Adam is murdered and Ethan becomes a prime suspect, Chloe’s sister Nicki (Banks) reenters her life to untangle a complicated family history and attempt to protect their son.

Adam is killed in the first episode so there are no spoilers there. Chloe finds him lying in a pool of his own blood in their Hamptons weekend home after she returns from an event. By the second episode, Ethan is arrested after his DNA is found at the crime scene. But if Ethan was the killer that would all be too simple so what’s the truth?

Who Killed Adam in ‘The Better Sister’?

In the finale episode it is revealed that Chloe’s sister Nicky killed Adam, her ex-husband.

Without Chloe or Adam knowing, Ethan had been secretly in contact with his biological mother. This explains why Nicky was so quick to delete the contents of Ethan’s flip phone after Chloe found it and asked her to charge it.

The night before Adam’s murder, Ethan tells Nicky that he saw his father physically assaulting Chloe while watching from the balcony of their New York penthouse.

Nicky immediately decides to drive from Ohio, where she is living and caring for Adam’s mother, and drive to the Hamptons to try to save her sister from the man who also abused her. Once there, she instead runs into Adam and confronts him, threatening to call the police. When Adam tries to attack her, Nicky stabs him with a pocket knife.

We then learn that Ethan was actually the first person to find Adam’s body, not Chloe. Believing that Chloe killed Adam in an altercation, Ethan tries to protect the woman who raised him by throwing things around the home to make it seems like an intruder broke in.

Who Gets Arrested for Adam’s Murder in ‘The Better Sister’?

Chloe manages to frame Bill Braddock (Matthew Modine) by planting the murder weapon in his home.

After Chloe learns incriminating information proving Bill knew that the Gentry Group had in a human trafficking scheme to get construction contracts pulled off. She also learns that Adam was working as an informant for the FBI so when the police raid Bill’s home and find the pocket knife, it’s assume he killed Adam in an act of revenge.

Earlier in the season, while Ethan is on trial for his father’s murder, Chloe testifies that she was having an affair with Adam’s friend and colleague Jake (Gabriel Sloyer) who knew about the abuse. Her testimony makes Jake another suspect in the case which allows Ethan to be found not guilty.

However, after briefly incriminating Jake and ultimately framing Bill, Chloe still has one person on her and Nicky’s case — Detective Nancy Guidry (Kim Dickens). Guidry does figure out that Nicky is the one who killed Adam by questioning Adam’s mother who informs her that Nicky knew details of the murder before the police contacted her, something only a culprit would know.

Before Guidry can pin it on Nicky, she is pulled off the case after Nicky digs up evidence that Guidry used excessive force and badly beat up an innocent Black man on a previous case and gets it released in an exposé article.

How Does ‘The Better Sister’ End?

The show ends with Nicky and Chloe being the only ones who know the truth about who killed Adam. However, in one more finale twist, a shot shows Jake’s dead body lying on a beach. It’s unclear how he died, something that is potentially a setup for a second season of the show.

The finale ending scene sees Chloe and Nicky sitting on the beach, seeming closer than ever. They discuss writing a memoir about what they’ve been through but Chloe tells Nicky, “I don’t have any story without you, not worth telling anyway.”

Before you go, click here to see more shows about the complexities of motherhood.