An awesome historical mystery. I think Jane and Arthur made a great team. I'm so looking forward to more twisty, top secret mysteries from this pair. It was hard not to read in one sitting.

Murder mystery set in 1941 England during the war.

Miss Jane Treen works at Whitehall overseeing a cadre of secret agents for Brigadier Remington-Blythe. Hard and driven, she’s a chain smoker with a serious coffee addiction. She has no desire to go chasing after missing agents out in the country out of her comfort zone, but needs must when another of her agents goes dark after being hidden away for her own protection at a safe house. She travels to Half Moon Manor to work with codebreaker and puzzle solver Arthur Cilento. He has returned from a work mission for the War Office to find a dead body in the river by his home. Could this woman be Jane’s missing agent? Thus begins a reluctant partnership as the two try to trace a complicated organization of what might be traitors to the British government.

Let’s see — it took me quite a while to get invested in this time period and story. I didn’t immediately warm to the main characters of Jane (annoying) or Arthur (sickly) and the set up of them being forced to work together. The plot and the many different side characters seemed overly complicated and there were a lot of deaths as Jane and Arthur chased around with only the most flimsy of clues. I was definitely happy that the cat in this book had limited involvement and infrequent mention.

The plot was convoluted and the denouement seemed rushed after all the suspects couldn’t really be interrogated. I’ll have to reserve my thoughts about where this series might be going and if I will follow it after I read the second book. Not sure this unlikely pair will hold my interest if there is more repetition about Jane’s smoking and coffee and Arthur’s asthma. I surely hope no romance between them as she seems a determined spinster and him a confirmed bachelor. Of course there is also the faithful man servant who seems to be essential to the detecting and is always behind the scenes greasing the wheels.

I was able to listen to the audiobook while also following along in the e-book ARC, both provided by the publishers. The performance of the narrator, Kristin Atherton, was excellent. She did a fantastic job with all the voices and the transitions were seamless. Her dramatic flair made the book so much more enjoyable.

London 1941. Secret government worker Miss Jane Treen is addicted to coffee and cigarettes. Unfortunately, her new partner prefers tea and is asthmatic. ‘The Secret Detective Agency’ is first in a new series of cosy mysteries by Helena Dixon, author of the 1930s Kitty Underhay detective books.
Starting the first book of a new series is always a risky thing, it takes time to set up characters, back stories, context and as a result the pace can be slow. But I enjoy the Kitty books and the wartime setting of ‘The Secret Detective Agency’ is another plus. Miss Treen works for an unnamed government department running Operation Exodus, her team of secret agents assist the escape of double agents from Germany to the UK. But Jane’s agents are dying and when Polly Flinders is killed at a safe house in Devon, Jane is sent to investigate. Her boss, referred to as The Brigadier, teams her up with asthmatic code breaker Arthur Cilentro. They make an unlikely pairing, especially in the first half of the book. Chain-smoking Jane brings her long-haired cat Marmaduke with her to stay at Arthur’s house, Half Moon Manor. While the two investigators sniff around, asking questions, squabbling and sulking as they go, Arthur’s manservant Benson is the grown-up.
This is a story of wartime spies, treason, double dealing and multiple identities with rather confusing code names. By the time Miss Treen and Mr Cilentro have relaxed together enough to call each other Jane and Arthur, the death toll has increased. Fuelled by gossip in an isolated wartime village where everyone’s business is well-known, the two detectives realise that everyone is a suspect.
It is inevitable that the trio – don’t forget the indispensable Benson, who is always on hand with the essentials without which Jane and Arthur would simply fail – will morph into a team by the end of this novel. I expected Arthur to be quite bookish; he is, but also a fussy bachelor with severe breathing problems and a sharp analytical mind. I expected Jane to be an efficient professional young woman from London, responsible for a top secret mission; she is, but as a detective on the ground she can be naïve and not tight-lipped enough. She also ignores Arthur’s asthma. I got a bit fed up of her blowing smoke in Arthur’s direction and letting her cat into his sitting room. Thankfully as the story progresses, the two learn to appreciate each other’s skills and their relationship becomes less spiky.
More a cosy wartime mystery than cosy crime, this is a good start to a new series which offers something different. Irritations aside, this was a quick enjoyable read. I enjoyed the wartime espionage setting and the idea of a government detective agency specialising in crimes too secret for the police. It’s easy to have unreasonably high expectations of a new series and, looking back to my review of the first Kitty Underhay mystery ‘Murder at the Dolphin Hotel,’ it too was a 3* read for me. I’m now a firm fan of Kitty and Matt’s investigations in 1930s Dartmouth.
Coming soon is the second instalment of Jane and Arthur’s investigations, ‘The Seaside Murders.’ Hints about Jane’s family background, including a glamorous actress mother, are sure to become storylines in future novels.
Read more of my book reviews at http://www.sandradanby.com/book-reviews-a-z/

A Detective agency in Whitehall!

An unusual spinster, an asthmatic mathematical intellect and his quite efficient manservant end up working for a secret agency within Whitehall.
It’s 1941. Jane Treen has been running agents for an important behind the lines operation.
When the operation appears compromised they were withdrawn. Jane had installed one with a minder in a safe house in Devon only she knew about.
Unfortunately that agent has turned up dead in a local pond found by Arthur Cilento who’s just arrived home from his own highly secretive war work. He’s quite annoyed that the people his house had been rented out to were Jane’s agents and no one told him.
We have here a somewhat different trio of people who are determined to solve the dilemma. Then there’s the questions. Who else has been compromised? Who’s behind this?
I was very cross by the chain smoking Jane who seems to have no thought for the asthmatic Arthur, focused as she is on her own concerns.
The manservant, Bensen, as always, contributes calmly.
I admit it became obvious there was a link in the village but the how and why was interesting.
A very treadable, cozy murder mystery/spy plot

A Bookouture ARC via NetGalley.
Many thanks to the author and publisher.
(Opinions expressed in this review are completely my own.)

Jane and Arthur have worked on secret projects before, as their country is in the midst of the war. However, they do not care for the other. When Arthur finds a body in the water outside his new home, Jane is brought in because it turns out her team is being targeted. As the two work together, they have to try to solve what is happening, while maintaining secrecy. There is more to come for Jane and Arthur (and Arthur’s new status as a cat uncle).

I always thoroughly enjoy Helena Dixon's mysteries and was curious about this one that starts a new series.
Set during WWII, featuring a heroine quite brash and strong, it's an entertaining story full of potential.
I enjoyed the characters and the setting, some more twists in the mystery would have make it great.
A good start for a new series, cannot wait to read the next one
Highly recommended.
Many thanks to Bookouture for this ARC, all opinions are mine

I’m constantly scouring shelves for cozy mysteries, especially British ones if I can find them, and this one absolutely scratched that itch! The mystery itself was engaging enough to hold my attention, while the developing relationship between the two main characters warmed my heart and left me rooting for them. So excited for the sequel!

I received a copy of this book from the publisher, but all opinions are my own. The Secret Detective Agency is the first title from Helena Dixon, who is best known for her long running Miss Underhay cozy mysteries. This series is set in Britain during WWII and features Miss Jane Trent, who works in Whitehall and was responsible for running an operation that placed agents in occupied France. She is forced to travel to the home of Arthur Cilento, who although of a weak constitution, contributes to the war effort by using his codebreaking and puzzle-solving skills. After some time away, Arthur discovers a body near a pond on his land that turns out to be an agent that was part of Jane's operation. She's not the first agent to die after coming home causing a frantic effort to figure out who is killing agents and why.

I overall enjoyed this title, but did think it suffered a little from first book in the series syndrome with the need to provide background not directly related to the mystery. Arthur and Jane are both engaging characters and the fact the they initially are like oil and water makes for some fun interactions. I thought the mystery had some great twists and turns and am definitely looking forward to future titles.

London, 1941: Miss Jane Treen is at her desk when her top-secret government work is interrupted by an urgent call to Devon. A woman has been found dead in a lake in a place where she shouldn’t have been. Shy and handsome code-breaker Arthur Cilento didn’t expect to find a body when he moved into the house he’d recently inherited, he is bewildered by the arrival of the efficient Miss Treen and her cat Marmaduke. She bursts into his life unexpectedly, forcing him out of his comfort zone.
The start of a new series & the pace began slowly then increased throughout the book. I liked both Arthur & Jane but feel as though I’m still getting to know them, I did love how they interacted, Jane is an all guns blazing person whereas asthmatic Arthur takes things far more slowly. They are aided by Benson Arthur’s valet cum butler cum medic. The body count does rise throughout the book & Jane becomes increasingly worried about why agents she’s been supervising are being murdered. There were plenty of twists & turns as well as red herrings before the climax & I was kept guessing as to who the murderer was. A well written series starter. I half listened & have read the book & thoroughly enjoyed the audio version, the brilliant narrator certainly brough the book to life
I voluntarily read and reviewed a special copy of this book; all thoughts and opinions are my own

It's 1941 and England is at war. It's not much better at home, where Arthur Cilento finds a dead woman in the lake in his garden. Not just any woman, but a secret agent! Jane Treen, another secret agent, comes to investigate the murder of her colleague. It is not the first death she's investigating. It seems someone is after her whole team.

Together with Arthur, Jane starts interviewing all Arthur's acquaintances, which seems to be almost everyone in the village of Devon. Everyone is a suspect. And while doing so, more murders occur. Who is behind these murders and will Arthur and Jane be able to stop them?

The Secret Detective Agency by Helena Dixon is a lovely cozy crime novel. It's full of intrigue and plot twists. It's characters are divers, there's someone to like for everyone. Perhaps a little over the top from time to time. I especially liked Benson, Arthur's manservant, who seems to be not only equipped to take care of Arthur, but also ready for any top secret investigation.

The novel is high paced and easy to read. A great whodunnit novel. I had no idea who the culprit was until the very end, so that kept me going throughout the book. I just needed to know who the killer was!

The Secret Detective Agency is the first in a series with the same name. The second book, The Seaside Murders, will be published shortly. It is already waiting for me, so another review is coming soon as well!

I’m not, in general, a fan of books set during war. However, I love Helena Dixon’s Miss Underhay Mysteries, so I decided to give The Secret Detective Agency a chance. I’m glad I did.

I was immediately sucked into the story, and I was particularly interested by the fact that Arthur has asthma. I have a chronic illness myself, so it’s good to see main characters who are not 100% healthy or able bodied. Though of course it depends on how they’re portrayed. In this case, I felt it was very well done, neither calling for pity, nor using the “triumph over disability” trope that is so exhausting.

I liked both main characters, though Jane seemed rather uncaring about Arthur’s difficulties with his asthma to start with. However, as the book went on, she took more care, and I warmed to her more.

The mystery was an interesting one, I couldn’t tell who the culprit was until the reveal. It was very satisfying to follow along as Jane and Arthur solved the mystery.

Overall, I really enjoyed this story. In spite of being set during a war (one of my least favourite settings), it was fun to read and definitely remained in the cosy category. I’m looking forward to the second book in the series, The Seaside Murders.

I was given a copy of this book, my opinions are my own.

One of my WWII cozy mystery series is ending this summer and I enjoy Dixon's Miss Underhay series, so when I saw she had a new series coming out, I knew I had to try it.

I was hoping for a story that I could lose myself in for a few hours but I had real trouble getting into this story. It was a little slow and there was some over-explanation. I didn't really like Jane Treen or Arthur Cilento.

It also bothered me that the backmatter is 12% of the book. For a 264-page book that is about 30 pages - it seems a bit much to me. Since I got the ebook for free to review it was only mildly annoying but if I paid for it I might be more annoyed so I believe it is important for you to be aware of this.

The characters did grow on me some as the book progressed and I enjoyed the mystery. If you read my reviews very regularly, you know that I often start cozy mysteries in the middle of the series. I do that partly because I often dislike the first book in the series. My lukewarm reception of this series may be related to that. This series has potential and I look forward to the next book in the series.

My review will be published on Sunday at Girl Who Reads - https://www.girl-who-reads.com/2025/03/the-secret-detective-agency-by-helena.html

A cozy mystery set during war-time England in 1941, this is a fun read with delightful characters. What starts as a seemingly simple whodunit is soon to be revealed to be a complicated mystery. Jane Treen relies on the help of code-breaker Arthur, though neither are thrilled to be working together. Despite not seeing eye to eye, they make a fantastic team and have started to get close to the truth when they realize there's someone right on their heels who is willing to kill to keep their secrets. Time is running out, and the safety of our heroes and of England depends on them solving this case.
I loved Jane - it's always wonderful to see a strong, smart female lead and every female character in this book was interesting and strayed away from stereotypes. I liked that we see Jane and Arthur grow to respect each other without it diving into romance. The plot kept me guessing - I definitely didn't solve this before the reveal! I haven't read many books set in England during this era and liked all the details such as blackouts and the ration books - it really drew me into the story and gave it a realistic feel. I also liked Jane's cat and hope he shows up in future books. I will recommend this book to my friends.

Book #1 in the Secret Detective Agency series, a golden age mystery series set in London, 1941 as the war continues to grow. Jane Teen is a field agent manager, who works with a cigarette in one hand and a cup of coffee in the other. She's on her way to Devon to investigate the death of one of her agents, bringing her cat along for the trip. She'll base her operation in the home of Arthur Cilento, a code-breakerwho's single, shy and asmathaic. Don't judge, the two of them will make an excellent team as they dedicate their efforts to insuring their agents are not targets.

The first books in a series move a little slower as they introduce the community and characters, setting arcs for future plot lines at the same time. This one follows that pattern but picks up pace as Jane moves into Arthur's house, cat and all. This was an excellent read and I'm looking forward to book #2.

The first in a new series The Secret Detective Agency and ira 1941 when we meet Jane Treen for the first time. Codebreaker Arthur Cilento has returned to his home in Devon to find a woman who shouldn’t be there, and what’s more she is dead! Jane Treen works in Whitehall for a secret government agency run by the Brigadier. A number of Jane’s agents have gone missing or been found dead and now another has been found at Arthur’s home. Jane and her cat and constant companion Marmaduke are soon en route to investigate.

Briefly, it is clear that Jane and Arthur need to work together albeit they certainly don’t hit it off at first, but the needs of the country come before their petty little squabbles. The list of potential suspects in the killings it long and someone is trying to best the British government. Not on Jane’s watch?

Jane isn’t immediately the most likeable character, she certainly isn’t at all like her namesake Miss Marple, although they both have an insatiable desire to solve the crime. This Jane is hard headed, very clever and a very heavy smoker, the latter of which is a big problem for asthmatic Arthur. He needs to man up a bit and tell her not to smoke in his house! That said it was an enjoyable plot and the killer was not easily detectable, just about verging on cosy it’s an entertaining golden age mystery and I’ll definitely pick up book 2.

Thank you so much to NetGalley and Helena Dixon for providing me with a complimentary digital ARC for The Secret Detective Agency coming out March 27, 2025. The honest opinions expressed in this review are my own.

I’ve read several books by this author. I really love historical cozy mysteries. I’m so excited that she started a new series. The time period is really interesting. I love stories about WWII. Jane Treen is a strong character. I really enjoy the direction of the book. It definitely feels like a Christie novel. There were a couple slow spots for me, but I loved it. I already have the second book in the series, so I will definitely be finishing that one soon.

I would recommend this book to anyone who enjoys cozy historical mysteries!

A delightful start to a new cozy mystery series by a wonderful author. I loved the characters, especially of course the main ones Jane and Author. Their newly formed and budding secret partnership will sure to be a great basis for future books. Looking forward to seeing what they get involved in next.
I received an advance copy of this book in exchange for my honest review.

I have a weakness for cozy mysteries and for British Homefront Novels from WWII. This series is right up my street. I was very impressed with plotting of this one, Ms. Dixon clearly knows how to write a mystery. There were moments of genuine peril, nothing too intense, and I could not discern the ending before it was revealed. Even more, I enjoyed the characters in this series. They are not revealed through explication, but through their actions (mostly). You feel like you have gotten to know them, but there is more to learn. The main character, Jane, is an independent woman who is not afraid to be the smartest person in the room. She does not seem hindered by her gender-she is exactly who she is at all times. Refreshing. The other protagonist, Arthur, is a bit mysterious, but I am enjoying getting to know him. I am enthusiastic about this new series, cannot wait to see what Ms. Dixon comes up with next. Highly Recommend.

It was 1941 London, and Jane Treen worked for a secret government agency run by the Brigadier, whose secretary Stephen, was a man Jane despised. But Jane's agents were dying at a rapid rate, and when the body of another was found at code-breaker, Arthur Cilento's home, Jane and her cat Marmaduke were soon on his doorstep in a small village in Devon. Needing to work together, under the Brigadier's orders, Arthur with his chronic asthma was desperate for her to leave. Jane smoked heavily, which upset his asthma...

As the pair worked together to unearth clues into who was betraying the British government, there were plenty of suspects to add to their list. As more deaths followed, they despaired of finding the answers they needed. Heading into London on the train, where the dreadful bombing was evident, Jane, Arthur and Benson, Arthur's man, were determined to reach the conclusions they sought. But would they?

The Secret Detective Agency is the 1st in a new series of the same name, by one of my favourite authors, Helena Dixon, who writes the Miss Underhay series. I was thrilled when I saw this new series, and am looking forward to #2 very much. Miss Jane Treen isn't a particularly likeable character, but I'm sure she'll grow on me. Arthur is wonderful and Benson reminds me of Clifford, Lady Eleanor Swift's butler, in the series by Verity Bright. All in all, a fabulous historical mystery which I loved. Highly recommended.

With thanks to NetGalley & Bookouture for my digital ARC to read and review.

I enjoyed this cozy mystery! The plot was very fun and all of the characters were likable. The only issue that I had with this book was the constant mention of the main characters asthma. It took away from my ability to enjoy the book because of how frequently it was mentioned. Other than that I loved it!

Thank you to NetGalley, the author, and the publisher for the ARC copy of this book.