Who was the killer on Netflix's The Thursday Murder Club? Explained

Netflix's The Thursday Muder Club, released on August 29, 2025, has smartly packed a great deal of humour, heart, and suspense in a film that has you guessing until the end. Based on Richard Osman’s (2020) best-selling novel, the crime-comedy tells the story of a group of unlikely investigators who live in a lovely retirement village and are confronted with a series of murders. 

Chris Columbus (Harry Potter and the Sorcerer’s Stone) produced the film, written by Katy Brand and Suzanne Heathcote. The cast is stellar, with Helen Mirren as ex-spy Elizabeth Best, Pierce Brosnan as ex-union activist Ron Ritchie, Ben Kingsley as ex-psychiatrist Ibrahim Arif, and Celia Imrie as ex-nurse Joyce Meadowcroft, and the main actors are only a drop in the ocean from all of the supporting actors, which include David Tennant, Jonathan Pryce, Naomi Ackie, and Richard E. Grant.

But who is the killer? Let’s solve the mystery and look at new perspectives on how this cosy whodunit reveals its deadly secrets.

The Killers revealed: A cold-blooded revenge in The Thursday Murder Club

Spoiler Alert: The film’s climax unveils a shocking chain of culprits. Peter Mercer, Angela Hughes’ boyfriend, killed her in 1973, driven by jealousy. Penny Grey, a former police officer and friend of the club, murdered Mercer in retribution, unable to bring him to justice officially. In the present, Bogdan, a local handyman, killed Tony Curran to protect Coopers Chase, as Curran’s shady dealings threatened the community. 

Finally, John, Penny's husband, poisoned Ian Ventham to thwart his development plans that threatened his wife's legacy. Each killer's motive, whether from love or loyalty or justice, is a human layer to the crimes, which then makes it all feel both heartbreaking and unexpected, particularly when it comes to resolution. The process of investing formally in The Thursday Murder Club continues with the support of the knowledgeable police officer Donna De Freitas (Naomi Ackie), and it's clear this is not just formal investigative know-how; it comes with human emotional context. 

The Thursday Murder Club explores a complicated web of motives

It all starts in Coopers Chase, a sleepy retirement village, where the Thursday Murder Club (which consists of Elizabeth, Ron, Ibrahim and Joyce) meets every week to discuss real-life unsolved crimes. Establishing from an interesting hobby, things take a darker turn when a shady contractor named Tony Curran (Geoff Bell) is murdered following a blunt-force trauma. Moments later, after a protest against his intentions to develop the retirement village into luxury flats, his business partner Ian Ventham (David Tennant) collapses, poisoned by the deadly drug fentanyl.

It is a cold case from 1973 about Angela Hughes, who was killed after falling from a window with a knife in her chest. This case is resurrected, leaving her present messy. The movie is entertaining because it is able to blend humour and emotional feelings regarding the retirees' struggle with their own mortality and wanting justice.

The film has streamlined Osman’s novel, leaving out subplots to ensure the pace was aligned to a 1-hour-58-minute duration, but keeping the novel's sense of humour and breadth of heart. Columbus's direction remains anthropogenic in its newcomer city-based mysteries, where darkness can be avoided by simply allowing the audience to embrace humour in any situation. Critics suggest the script could be sharper, but the underlying excitement of the film rides on the chemistry of the cast, and the motivation of the killers clearly exceeds the tropes of the classic whodunit film.

Where to stream The Thursday Murder Club

The Thursday Murder Club is streaming right now on Netflix. It’s been available since August 28, 2025, at 8:00 am BST. You are missing out if you haven’t watched the film yet. 

Stay tuned for more updates!