The Better Sister wrapped up its limited series run on Prime Video, but how did this twisted mystery series end? We break down the ending to explain it.
Caution: This article contains SPOILERS for The Better Sister
The Better Sister opens with Chloe (Jessica Biel), a wealthy and successful magazine editor, coming home to find her husband Adam (Corey Stoll) murdered. The investigation is overseen by Detective Nan Guidry (Kim Dickens).
Guidry soon learns the strange dynamic when Chloe’s estranged sister Nicky (Elizabeth Banks) comes to town. Nicky had been married to Adam first and the mother to their son, Ethan. However, she lost custody when Adam reported that she’d gotten drunk and fallen into the pool with Ethan nearly drowning. That sent Nicky out of town and into a depression of drugs and drinking, while Adam ended up marrying Chloe and raising Ethan with her.
Just to make things more complicated, Chloe has been having an affair with Jake (Gabriel Sloyer), Adam’s business partner and their neighbor. Jake, in turn, is being pressured by the FBI to get some evidence on the Gentry Group, the powerful firm he and Adam work for, run by Bill Braddock (Matthew Modine).
Eventually, the police find evidence Ethan (Maxwell Acee Donovan) was into shady stuff with drug dealers and arrest him for his dad’s murder. With Michelle Sanders (Gloria Reuben) defending him, Chloe and Nicky are forced to overcome their problems to help their son.

The strange mysteries abound on The Better Sister
As the case gets major attention, Chloe has to handle possibly losing her job with her boss and mentor Catherine (Lorraine Toussaint) sympathetic but has to look at the business side of things. Chloe is also trying to figure out who killed Adam, with suspicions of anyone from Braddock to some stalker.
It slowly comes out that Adam was not the great husband Chloe told everyone he was. He was controlling, arrogant, and also abusive to her. Taking the stand at Ethan’s trial, Chloe confessed to Adam hitting her. She also claimed to have told Jake about it, giving him a motive to kill Adam. Jake himself pleaded the fifth when he was on the stand.
With such reasonable doubt, Ethan was found not guilty. At home, Ethan confessed he had found his dad dead and messed up the crime scene to look like a robbery because he figured Chloe murdered him, with her denying it.
As if things couldn’t get more messed up, two more curve balls occurred. First, Chloe and Jake had it out over her using him to save Ethan. Jake revealed that he was working with the FBI to get information on how the Gentry Group was using illegal labor for projects and, in essence, engaging in human trafficking.
Then, Ethan uncovered police reports on that long-ago supposed drowning that showed he’d never been close to drowning while Nicky’s system indicated she was drugged. In other words, Adam had drugged his then-wife and staged her “drunken breakdown” to get custody of Ethan. Chloe imagined a conversation with Adam defending himself on doing what it took to "save" his son and showing his true colors as a selfish control freak.
That broke Chloe down, with Nicky saying she would do anything for her sister…including murder.

Did someone get away with murder in The Better Sister?
The finale revealed the truth: Nicky killed Adam. She’d known for years how Adam had set her up but couldn’t prove it and knew Chloe wouldn’t believe her. When Ethan called her to tell how he’d seen his father hit Chloe, Nicky left her phone behind in Ohio (so anyone tracking it would think she was there), drove to New York to confront him and when he attacked, she stabbed him in self-defense before returning to Ohio to complete her alibi.
Chloe decided she wasn’t going to let her sister be put through even more pain, and together, they hatched a wild plan. Chloe first dropped a tip to the FBI about the agent harassing Jake. She then went to Braddock to hand over files she’d discovered about the Gentry Group’s actions, saying she wanted nothing to do with this and clear Adam’s debt to them.
Meanwhile, it looked like Nan was about to break it all wide open by traveling to Ohio, talking to Chloe and Nicky’s mom, and how Nicky had known about the murder before she was called about it. Nan triumphantly called her boss to say all they needed was a DNA check, and Nicky would be arrested.
Her boss had to break it to Nan how Nicky was a step ahead. She’d uncovered Nan’s history of abuse and breaking laws. That included how Nan had once brutally beaten a black suspect to the point the guy was now mentally incapacitated and, worse, wasn’t involved in the crime at all.
As soon as that story was spread by Catherine, Nan’s case against Nicky went up in smoke. She was already put on leave, meaning she had no authority to get DNA evidence and possibly lose her badge with any accusations against Nicky dismissed as a violent cop trying to save herself.

Then, the police descended on Braddock’s apartment as Chloe had made copies of the files for the cops. They also found the knife that killed Adam that Chloe had planted. At a bar, Nan stared in disbelief at the news of Braddock being arrested for Adam’s murder.
Despite some tension over Chloe wanting a book deal about all this and Ethan’s guilt, the season ended with the sister sitting outside admiring the stars. They had gotten away with murder, although it was hard to feel sorry for Adam’s death. It was a dark end to the show yet oddly uplifting as the sisters had overcome their longtime problems and were ready to move on from this tragedy together.
It was a wild ending, yet it also worked for the show to bring the compelling mystery to a close, and the cast made The Better Sister a fun novel adaptation that’s worth the watch.
The Better Sister streaming on Prime Video.
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