The Better Sister Book Ends In An Unexpected Twist

Jessica Biel and Elizabeth Banks play sisters with big secrets in Prime Video’s new murder mystery, The Better Sister. The series (out May 29) is based on Alafair Burke’s hit novel of the same name, which follows estranged sisters Chloe and Nicky (played by Biel and Banks on screen) whose worlds collide over a shocking event: Chloe’s husband, Adam — who used to be Nicky’s husband! — is murdered at home.

Viewers will have to watch to see if the series sticks to the page. As Biel told Gold Derby, she was “shocked” by the killer reveal. And for Banks? “I think it was the exact right person,” she said of the “satisfying” conclusion.

So... what happens in the book? If you’d like a peek ahead, here’s the plot summary and book ending of The Better Sister.

A Complicated Family Tree

Chloe is a successful journalist living in New York City with her husband and son, Ethan. Only, Ethan is technically her step-son. Adam divorced Nicky after finding her drunk and passed out in the pool with baby Ethan, who nearly drowned. Eventually, Adam moved to the city and began a relationship with Chloe, who opted to raise Ethan as her own, deciding Nicky’s destructive habits made her unfit as a mother.

One evening, Chloe returns to the family’s Hamptons beach house to find Adam stabbed to death. Ethan is arrested in connection with the crime after inconsistencies with his story lead police to suspect him.

Nicky travels from Ohio to be with Chloe as the family awaits trial. During this time, the estranged sisters begin to reconnect, and Chloe learns more about the abuse her older sister witnessed and endured growing up.

The Better Sister’s Big Twist

The trial uncovers several disturbing developments, including the fact that Ethan knew Adam was hurting Chloe behind closed doors. Chloe’s defense team brings in Adam’s co-worker, Jake, with whom she’d been having an affair. It’s all in hopes that he might deflect suspicion from Ethan, whose innocence even Chloe begins to doubt.

The strategy works, and Ethan is found not guilty. But after the trial, the real killer privately confesses to Chloe. It’s Nicky.

Nicky had been in secret contact with Ethan in the months leading up to Adam’s death. After she learned about Adam’s abuse — he’d also begun to gaslight Ethan — Nicky drove to New York to confront him, leading to the fatal stabbing.

The sisters also piece together that Adam had staged Nicky’s pool accident with Ethan all those years ago to get custody.

Chloe decides not to turn Nicky in, and instead, the sisters and Ethan start a new life together in New York.

If you or someone you know is experiencing domestic abuse, call 911 or the National Domestic Violence Hotline at 1-800-799-SAFE (7233) or visit thehotline.org.