The Beast Must Die: release date, trailer, plot, cast and everything you need to know

The Beast Must Die
Cush Jumbo and Jared Harris star in thriller The Beast Must Die (Image credit: Britbox)

Thriller The Beast Must Die, based on a 1938 novel by poet Cecil Day-Lewis (father of Daniel), has been adapted into a new drama series for Britbox, starring Jared Harris (The Crown, Mad Men, Chernobyl) and Geraldine James. 

The story centers on Frances Cairns, played by Cush Jumbo (The Good Fight), a bereaved mother trying to find the driver who killed her son in a hit-and-run accident. 

Self-made man George Rattery (Jared Harris) becomes her prime suspect, and she finds a way to meet him and his sister Joy (Geraldine James) to find out more. 

Meanwhile, newly transferred local police detective DI Strangeways (Billy Howle) is also traumatized by the recent death of his colleague, DI Dixon. 

The Beast Must Die plot

After learning that the police investigation into the fatal hit-and-run of her son, Martie, on the Isle of Wight has been dropped, Frances Cairns secretly vows to find her son’s killer herself. 

Following a trail of clues, Frances tracks down Lena, the suspected other passenger in the car at the time of the accident. Sparking a friendship with Lena under the cover story of needing research for a fake novel she’s writing, Frances manages to find out that the person driving the car on that fateful day may have been Lena’s brother-in-law, George Rattery. 

With some gentle manoeuvring, Frances manages to get an invitation to Lena's sister Violet's birthday party. Arriving at George’s palatial home Frances finally gets to lay eyes on who she believes is her son’s killer and also meets Joy, George’s sister.

Elsewhere, DI Nigel Strangeways, suffering from PTSD after the recent death of his colleague DI Shannon Dixon, arrives on the Isle of Wight where he has been transferred to take over from the recently deceased DI Geraghty at Newport Police Station. 

He is the one to tell Frances that the case into Martie’s death has been deemed No Further Action. Meanwhile, after a tense appearance at the memorial of DI Dixon, Strangeways learns that his deceased colleague’s sister, Niamh, has decided to file a complaint against the police for negligence. This is the last thing Strangeways wants to be dragged into right now.

The Beast Must Die cast

Jared Harris (The Crown, Mad Men, Chernobyl) plays George Rattery and Geraldine James plays his sister Joy.

Cush Jumbo plays bereaved mother Frances Cairns and Billy Howle plays DI Strangeways.

The Beast Must Die trailer

The Beast Must Die trailer has dropped! 'You know what a fraudster is...they make you feel wanted!' says Jared Harris as George Rattery. All very intriguing and It looks stunning too! 

The Beast Must Die release date

In the UK, The Beast Must Die was first shown in May 2021 and is now available to watch on BritBox in the UK. AMC picked it up for the US and it was aired in July 2021.

It will become available on ITVX from Monday May 6 2024.

Ian MacEwan
Senior Writer

Ian writes about TV and film for TV Times, What’s on TV and TV & Satellite Week magazines. He co-hosts the weekly TV streaming podcast, Bingewatch.