How Many Episodes in The Marlow Murder Club Season 3? Full PBS Guide

There is something wonderfully old-fashioned about The Marlow Murder Club. No serial-killer obsession. No miserable detectives staring at walls for six hours. No endless shots of rain hitting a police station window.

Instead, we get three women, a picturesque English town, suspicious neighbors, ridiculous secrets, and enough murder to make you question whether anyone in Marlow actually knows how to behave.

That is exactly why I was looking forward to The Marlow Murder Club Season 3.

The third season brings Judith Potts, Becks Starling, and Suzie Harris back for another round of amateur detective work, with new murders, new suspects, and another collection of people who apparently cannot attend a dinner party without someone ending up dead.

And yes, the first thing most viewers want to know is simple: how many episodes are in The Marlow Murder Club Season 3?

The answer is six episodes.

But there is a little more to that number than it might suggest.

How Many Episodes Are in The Marlow Murder Club Season 3?

Season 3 has six episodes, following the format established by the previous season.

Rather than stretching one murder across six episodes, the season is divided into three separate mysteries, with each case receiving two episodes. Personally, I think this is one of the smartest things the series has done.

A cozy mystery needs room to breathe. We need time to meet the suspects, notice the strange details, suspect the wrong person, change our minds, and then hopefully slap our foreheads when the solution finally arrives.

Each mystery gets that opportunity.

Episodes run for roughly 45–50 minutes, giving each two-part case enough space to build momentum without becoming unnecessarily bloated.

That matters. One of my biggest complaints with modern mystery television is how often a fairly simple murder gets stretched into an eight-hour ordeal. The Marlow Murder Club generally knows when to keep things moving.

The Marlow Murder Club Season 3 PBS Schedule

For viewers in the United States, Season 3 begins airing on PBS Masterpiece on Sunday, September 6, 2026.

The scheduled episodes are:

• Episode 1 — The Queen of Poisons, Part One: September 6
• Episode 2 — The Queen of Poisons, Part Two: September 13
• Episode 3 — Murder in the Dark, Part One: September 20
• Episode 4 — Murder in the Dark, Part Two: September 27
• Episode 5 — An Appetite for Murder, Part One: October 4
• Episode 6 — An Appetite for Murder, Part Two: October 11

The US broadcast slot is 8:00 PM Eastern / 7:00 PM Central.

So, if you are planning a proper Sunday-night mystery ritual, the schedule is pleasingly straightforward. Six Sundays. Three murders. One very suspicious town.

And honestly, that sounds pretty good to me.

Episode 1 & 2: The Queen of Poisons

Season 3 opens with The Queen of Poisons, based on Robert Thorogood’s novel of the same name.

The setup is deliciously nasty.

During what should be a painfully dull local council meeting, Marlow’s mayor, Geoffrey Truman, suddenly collapses and dies.

Except this isn’t a natural death.

He has been poisoned with aconite, a notoriously dangerous plant toxin also known as the “Queen of Poisons.”

Naturally, the investigation immediately becomes complicated.

One of the obvious suspects is Sophia Hollingbury, a keen gardener who happens to have access to poisonous plants. That’s almost too convenient, which is precisely the sort of thing that should make Judith suspicious.

And it does.

The investigation pulls Judith, Becks, and Suzie into a mess involving political maneuvering, financial corruption, blackmail, and secrets buried beneath Marlow’s respectable exterior.

This is the kind of story the series does best. The murder itself is interesting, but the real entertainment comes from watching the trio dismantle everyone’s carefully constructed stories.

My only concern here is that the “obvious suspect who is probably too obvious” structure is hardly new. The execution will have to be sharp to keep experienced mystery fans guessing.

Still, the premise is strong enough to get the season off to a very promising start.

Episode 3 & 4: Murder in the Dark

The second case gets considerably more personal for Becks.

She heads to a university reunion expecting nostalgia, awkward conversations, and probably far too much alcohol.

Instead, someone gets murdered.

The group is playing the classic party game Murder in the Dark when the joke suddenly becomes horrifyingly real. One of the participants is found stabbed, and Becks finds herself dangerously close to the center of the investigation.

Worse, she becomes a serious suspect.

That gives Season 3 something I always like seeing in this series: the three protagonists aren’t simply wandering around solving someone else’s problem. One of their own is in trouble.

Judith and Suzie have to work alongside the police to clear Becks’ name while digging into the old relationships between the university friends.

And old friendships are rarely as innocent as they look.

This storyline could easily become my favorite of the season if the writers really lean into the uncomfortable history between the characters. Reunion mysteries have a built-in advantage: everyone knows everyone, everyone remembers something different, and somebody is almost certainly lying.

Episode 5 & 6: An Appetite for Murder

The final mystery moves into the world of celebrity chefs and high-end food.

A famous but notoriously difficult chef arrives in Marlow for a major new venture. Things are going well — until the chef is murdered during a high-profile event.

Suddenly, everyone has a motive.

There are unhappy employees, professional rivals, personal enemies, romantic complications, and plenty of people who would probably be delighted to see the chef’s career collapse.

Unfortunately for them, someone takes things much further.

An Appetite for Murder sounds like the most playful case of the three, and that could be a very good thing. After political corruption and a murder at a reunion, a culinary-world mystery feels like exactly the sort of tonal change the season needs.

I am particularly hoping the writers don’t make the celebrity chef merely a cartoon villain. The best Marlow Murder Club suspects are people who seem perfectly plausible at first and increasingly questionable as Judith starts pulling at loose threads.

Who Is Returning for Season 3?

The central trio remains intact, which is obviously essential.

Samantha Bond returns as Judith Potts, the retired archaeologist and crossword setter whose brain is basically a crime-solving machine. Judith remains the intellectual engine of the group, and Samantha Bond continues to be one of the biggest reasons the show works.

Jo Martin returns as Suzie Harris, the practical, observant dog walker who often brings a more grounded perspective to the investigations.

Cara Horgan returns as Becks Starling, whose respectable public image contrasts nicely with her growing enthusiasm for amateur detective work.

Also returning is Natalie Dew as DI Tanika Malik, who has moved beyond simply tolerating the trio’s interference. Their unusual partnership has become a genuine part of the show’s appeal.

Season 3 Guest Cast

There are some particularly interesting additions to the guest lineup.

Peter Davison appears as Mayor Geoffrey Truman, whose death launches The Queen of Poisons.

Sarah Alexander plays Sophia Hollingbury, the gardener who quickly finds herself under suspicion.

Davison is especially welcome casting for British television fans. Putting a familiar face into a murder mystery is always fun because you immediately start wondering whether the actor’s reputation is being used to distract you.

And yes, I will absolutely suspect everyone.

Where Can You Watch The Marlow Murder Club Season 3 in the US?

US viewers have several options.

The simplest is PBS, where the third season airs weekly on Sunday nights beginning September 6.

Episodes are also expected to be available through the PBS App and PBS streaming platforms, although availability can depend on the viewer’s local PBS station and the streaming window.

For viewers who want longer access to episodes, PBS Passport is the more convenient option. The membership benefit typically provides extended on-demand access to PBS programming.

There is also the PBS Masterpiece channel through Prime Video, giving Amazon users another way to follow the season without relying on traditional television.

So whether you are watching on Sunday night or catching up later, there should be a fairly painless way to follow all six episodes.

The Marlow Murder Club Season 3: US Release Date, PBS Schedule, Cast, and Plot Spoilers

Is The Marlow Murder Club Season 4 Happening?

According to the information surrounding the series, Season 4 has been renewed, with a potential 2027 release window.

The proposed format is expected to remain familiar: six episodes divided into three two-part mysteries.

One especially interesting possibility is an adaptation of Murder on the Marlow Belle, another Robert Thorogood mystery.

That would make sense creatively. The series has already established a formula that works, and there is no obvious reason to throw it away.

Still, I hope the writers resist the temptation to make Season 4 bigger simply for the sake of being bigger. The Marlow Murder Club works because it feels intimate. The murders matter, but so do the friendships, the town, the odd little characters, and the humor between the investigations.

My Take on Season 3

Six episodes is probably the right number.

I would rather have three properly developed mysteries than one oversized plot stuffed with filler. The two-part structure also gives each case enough space to feel like a complete story rather than another television puzzle that gets solved five minutes before the credits.

The biggest challenge for Season 3 is originality.

The Queen of Poisons has the classic poison-and-politics setup. Murder in the Dark has the suspicious reunion formula. An Appetite for Murder takes us into the familiar world of arrogant celebrity chefs and jealous rivals.

None of those concepts is revolutionary — and thankfully, they don’t need to be.

The real question is whether the characters make them entertaining.

Judith, Becks, and Suzie are the reason I keep coming back. Their friendship gives the murders personality, and their chemistry prevents the show from becoming another grim British crime drama where everyone looks exhausted all the time.

That’s the charm.

The Marlow Murder Club Season 3 has six episodes, three mysteries, and plenty of reasons for cozy-crime fans to clear their Sunday evenings. If the new stories maintain the balance between clever puzzles, eccentric suspects, British humor, and the increasingly entertaining relationship between the three amateur sleuths, this could be another very satisfying chapter for the series.

Just don’t trust the gardener.

You never trust the gardener.