Prime Video has the best crime thriller series I've seen this year — but the ending shocked me

When I first started watching The Better Sister on Prime Video, I knew it was going to be a good series. As a rule, I love any crime drama that is based on a best-selling book, and so this eight-part twisty-turny thriller was right up my street.

However, as the episodes went on, I knew this show would be one to keep me on the edge of my seat until the final moments — and the ending definitely didn't disappoint.

The series, which is based on the novel by bestselling author Alafair Burke, stars Hollywood favourites Jessica Biel as Chloe and Elizabeth Banks as Nicky — 'rival' siblings who have their mysterious past brought to light after the shocking murder of Chloe's husband, Adam.

But this isn't just a whodunnit murder mystery — this is a show that goes much deeper than that, diving into sibling rivalry and past trauma, which is the foundation for the entire story that unfolds between Nicky and Chloe.

Without giving too much away, just in case you haven't watched it, Chloe's husband Adam is found murdered in his own home at the start of the very first episode. However, as the police try and work out who killed him, they are suspicious when Chloe and her teenage son, Ethan, don't seem too traumatised about the fact that Adam is dead.

But, while that is explained later on in the show, we then meet Nicky, Chloe's estranged sister, who, in the first twist of the series, turns out to be Ethan's biological mother.

Soon, the world isn't just talking about murdered Adam, they are more interested in Chloe and Nicky's dark past, especially when it is revealed that Adam was once married to Nicky, before leaving her and marrying Chloe whom he raised Ethan with.

The reality of what really happened between Nicky and Adam is something no one could predict, and I almost found myself forgetting this is a story about trying to catch a killer.

But, it was the ending of the show that really shocked me — mainly because just as it seemed the whole drama was tied up neatly with a bow, with all the questions answered, one single shot of a dead body lying on a beach turned the whole thing on its head.

I won't reveal who the unfortunate character who has met their maker is, just in case you want to watch, but it definitely opens up the show for a second season.

I left the series with more questions than answers and formulating an email in my head to producers begging for more episodes.

Could this be the most intriguing and gripping thriller for 2025? I think it's definitely up there as a strong contender.

All eight episodes of The Better Sister are on Prime Video now.