The Mistletoe Murder Club: Book 4 in the Bad Girls Detective Agency Series

Last Updated on August 6, 2026

Before diving into the new Christmassy case in The Mistletoe Murder Club, a primer on the Bad Girls Detective Agency (BGDA) is in order for newcomers.

The Agency, founded by the irrepressible Amber, brings together three women – Amber herself, Jeanie, and Clio – each facing midlife with more resilience (and baggage) than they care to admit.

Across the first three novels, which are How Not To Murder Your Ex, Murder on the Dancefloor, and Murder on the Menu, they’ve battled personal woes, frenemy drama, and a mounting body count, all with tip-top banter and a slightly irreverent attitude toward both crime and midlife crisis.

Amber, an ex-police officer with trust issues and a knack for detecting, leads the group with competence and compassion.

She’s grappled with the agency’s financial struggles and her own skepticism, which add real stakes to her sleuthing.

Jeanie, meanwhile, juggles childcare, comic mishaps, and increasingly sharp detective skills.

And Clio, the actress whose best roles seem forever behind her, is always up for a new escapade, despite her not-so-glamorous current career as a private detective.

Together, these three women provide the emotional core of the series. Their friendship has only grown, and author Katie Marsh’s signature mix of affection and exasperation keeps their camaraderie genuine and relatable.

Their past adventures have included “locked room” mysteries, Cluedo-style mayhem, and plenty of moments when you’re rooting for them even as chaos reigns.

So now you have a bit of a back story, let’s take a look at the 4th book, a timely Christmas-themed cozy mystery that is perfect for the holiday season.

It’s Panto Season

In The Mistletoe Murder Club, named as a bit of a joke because it’s Christmas week, sees the trio lured into festive danger when Clio snags a lead role in the village pantomime, Jack and the Beanstalk.

Clio hopes the stage might reignite her fading stardom and maybe even impress some local critics.

But everything unravels when the panto’s formidable director, Dame Beatrice Butler, is murdered on opening night.

The panto quickly goes from slapstick to sinister, and it’s clear there’s more drama off-stage than on it.

When it becomes apparent that several cast members had motives (and may even have already tried to kill her), the plot thickens faster than Christmas pudding.

With her colleagues, Amber and Jeanie donning a pantomime cow costume for undercover sleuthing, the investigation takes on a fun but dangerous edge.

Clio’s big break might be her last as the murderer stalks the wings, intent on bringing the curtain down on all three of them, forever.

Festive Flair & Tone

Katie Marsh excels at weaving warmth and humor into a plot that brims with suspense.

The Christmassy setting is joyfully rendered, from tinsel-strewn rehearsal rooms to chilling midnight confrontations in the wings.

References to classic pantomime tradition are sprinkled throughout, providing British cozy mystery fans with a real treat.

The characters banter and blunder their way through the investigation, their mishaps and midlife musings bringing relatability and genuine heart to the story.

Marsh’s dialogue sparkles with wit, and her depiction of a close friendship that is fraught, funny, but unbreakable, remains the series’ greatest strength.

So, even though you can absolutely read The Mistletoe Murder Club as a stand-alone novel, the first three books give you more insight into the bonds and lives of the three women.

Solid Central Mystery

This is one of the aspects I liked most about the book. When Dame Beatrice is murdered, it would be easy for us readers to feel incredibly sorry for her.

After all, she’s an older woman, widowed and just trying to stay relevant while keeping her legacy alive.

However, there are chapters interspersed that count down the time until she is killed, written from her perspective, and let me tell you, she is not a good person.

While funny to read, she is a complete narcissist and there are no lengths to which she will not go to get what she wants.

So much so, that it’s amazing somebody didn’t bump her off long before the panto!

Which of course means that there are multiple attempts on her life and more suspects than you can shake a stick at.

Nearly everyone involved in the panto had a reason to want Dame Beatrice dead, and untangling the shifting alliances and secrets makes for great reading.

The pacing is quick, with enough red herrings, secret grudges, and backstabbing to please even the most seasoned armchair detective.

Verdict: A Festive, Feel-Good Whodunit

The Mistletoe Murder Club is a prime example of why the cozy mystery genre continues to thrive: memorable characters, clever plotting, and that all-important dose of holiday cheer.

Fans of Richard Osman, Tonya Kappes, and Debbie Young will feel right at home here. Marsh’s signature wit, affection for her protagonists, and love of the genre make this a standout seasonal read.

You’ll race through the pages, grimace at the clues, laugh at the cow costume hijinks, and wish you were spending Christmas with the Bad Girls Detective Agency – though perhaps from the safety of the audience!

And if you haven’t read the earlier entries, don’t worry: Marsh subtly weaves in backstory, making this a great festive jumping-on point.

But fair warning: you’ll find yourself wanting to devour the whole series.