Death by Diamond: A 1920s Cozy Mystery

Lady Ellen Investigates #5

by Kelly Mason

Lady Ellen settles back into life at Ashcombe Hall and eagerly awaits the return of Captain Ernest Hamilton from Cairo. But her peace is shattered when a notorious thief is found dead on the neighbouring Worthington estate. Heading over to console Lady Jane Worthington, Ellen’s day takes an unexpected turn – a plane crashes on her land, piloted by flame-haired Alex, the Duke of Loxborough, who is once again masquerading under a pseudonym. As charming as he is, Ellen is unnerved by his presence – she does not trust him.

Ellen discovers that the dead thief had been attempting to steal a pair of rare pink diamonds, recently acquired by Lord Worthington and rumoured to be cursed. Though Ellen would prefer to leave the matter to the police, Jane’s pleas – and Alex’s insistence on staying in Ashcombe until the case is solved – draw her reluctantly into the investigation. She wants the mystery and Alex gone before Hamilton returns!

Genres: Cozy Mystery

246 pages, Kindle Edition

Published March 29, 2025

About the author

Hi, I love writing mysteries and started with a paranormal series. In the last couple of years I have been writing 1920s mysteries. I love the atmosphere of the time, that has been depicted on our screens and in fiction. Of the fashion, the cars, the parties following the war which gave everyone that 'live for the day' attitude.

I set my books in Somerset close to where I live, although the towns and villages are fictional they are based on real places local to me. They have to be fictional as I change them to fit the story. I do use the real cities though, such as Bristol and Bath Spa. They are places I visit often and it's great to be able to spend time researching what the cities were like 100 years ago.

I hope you enjoy reading my books.

Reviews

[Deborah · Rating 5 out of 5]

Lady Ellen has finally returned home to her newly renovated Ashcombe Hall following her extended break in Brandon Bay. A break filled with murder and investigations. She’s looking forward to settling back into a quieter life, along with the new staff and friends she made while away.
Her plans are dented by her neighbour and old school chum, Lady Jane Worthington, who is determined to reintroduce Ellen to society, whether she wishes it or not. Which she definitely does not. Having finally come to terms with, and declared her affection for, Captain Ernest Hamilton, a man of the middle classes, Ellen has no wish to suffer the disapproval of her peers. Much simpler to keep herself to herself and avoid potential unpleasantness.
However, when a dead man is found in a river on the boundary of her estate with one of Lady Jane’s supposedly cursed pink diamonds lodged in his windpipe, and the annoying, secretive Alex crash-lands his plane in one of her fields, how can Ellen not become involved?
With Ernest abroad, Alex attaches himself to Ellen’s investigation, causing her to experience much confusion about her feelings for the two men in her life. The mystery of how the second diamond reappears in the safe it was stolen from leads them to suspect the temporary staff in Jane’s home. With limited suspects, all of whom appear to have solid alibis, Ellen is faced with a conundrum that thankfully, for once, does not involve the police. Until the unpleasant Inspector Stone appears on an unrelated matter. Or is it?
As ever, a beautifully written book with an intriguing mystery, vivid characters with plenty of emotional depth, excellent dialogue, and a satisfying twist in the tail. The ongoing threads of Lottie and Sebastian, and the question over the identity of the Vigilante Slasher continue to draw us into the next story, which I am looking forward to.

[Paige Moulton · Rating 5 out of 5]

Death by Diamond by Kelly Mason is an engaging 1920s cozy mystery that combines elegant historical atmosphere, clever investigation, and charming character dynamics into a captivating addition to the Lady Ellen Investigates series.

One of the novel’s greatest strengths is its richly developed setting. The world of 1920s aristocracy, country estates, and social expectations creates a fascinating backdrop for a mystery filled with secrets, hidden motives, and unexpected discoveries.

Lady Ellen remains a compelling protagonist whose intelligence, determination, and sense of justice drive the investigation forward. Although she would prefer to leave the matter to the authorities, her loyalty to those around her and her natural curiosity pull her into a dangerous mystery involving a notorious thief and a pair of rare pink diamonds.

The mystery itself offers an enjoyable blend of suspense and classic cozy elements. The rumored curse surrounding the diamonds, the suspicious circumstances surrounding the theft, and the arrival of unexpected characters create an atmosphere of intrigue that keeps readers searching for answers alongside Ellen.

Another standout feature is the character interplay, especially the tension surrounding Alex, the Duke of Loxborough, and Ellen’s complicated feelings about his presence. The balance of mystery, charm, and personal conflict adds additional depth to the story.

For readers who enjoy historical cozy mysteries, 1920s settings, clever investigations, strong female protagonists, and stories filled with elegance and intrigue, Death by Diamond delivers an entertaining and atmospheric mystery experience.

[Tali · Rating 4 out of 5]

Glad we finally get to see the hall and Ellen in her home element, was excited about that for this one and that aspect did not disappoint!
I love this series but I flinched and was disappointed when Alex showed up because I hated him so much last time he was around. He has not grown on me, however despite my misgivings for the first 30 minutes of his arrival (I listen on audio) of course the writing, the mystery, and the rest of the cast of characters that I love had me engaged and excited again despite my Alex hate. Also I do always feel super satisfied when I’m right about a prediction regarding the mystery which happened this time.

I have a major theory we shall see how that plays out I hope it goes the way I want it to but could be a red herring but here’s hoping. It would be a good pay off. If the pay off is worth it then this will change to a five star review for sure.

Was very excited to find that another audiobook in the series had released this month so will listen to that soon as I love this series.

[Anne Newman · Rating 5 out of 5]

An interesting title and it was the cause of a death! Lady Ellen, Lottie & Prince the dog had been to visit Lady Ellen’s next door neighbour, Lady Jane, hearing about two beautiful pink diamonds that have been cursed. On the way home they notice two men dressed in black in the distance. Taking them for poachers they quickly got themselves home. The next day, one of those men was found caught In the reeds in the river that divides the properties. One of the diamonds was in the dead man & the other was discovered back in the safe! Poor Lady Jane is totally upset by it all. Adding to all the fuss & bother, a plane lands in one of Lady Ellen’s fields & it is someone with questionable ethics she feels. An enjoyable read with several twists and turns.

[Bks43v3r]

Unrated

I started this book last spring and then stopped. I can't even recall why. I think I meant to pick it back up. But it has almost been a year, so I am officially declaring it a DNF.

I have read 2-3 of the other books in this series (not all in order). They were okay. It's a well established trope. Rich, titled English woman who solves crimes. There's often, as in the case of this book, a lady maid/companion sidekick. And sometimes, again as in this case, a possible love interest. In this book, there's someone else who want to compete for her affections. Love triangle? I did not get that far.

I may pick it back up in the future. However, I have A LOT of books on my TBR list...so maybe not.

[Carol · Rating 5 out of 5]

And Ellen thought that her mystery solving days were over!! But when a dead body washes up in her boundary river, her neighbour's pleading didn't giver her much choice to walk away, especially when the theft of the famous Grovesnor Pink diamonds were also involved.

Another good read, looking forward to seeing what happens next!!

[John Nino · Rating 5 out of 5]

another success for Lady Ellen

Swell conceived plot with excellent dialogue throughout. Good character development. Enough twists and turns to really confuse you. Rough to a wonderful ending. Good entertainment. Recommend reading. What will happen with Ernest Hamilton?

[Julie Burnett · Rating 4 out of 5]

Another hit, characters we know but new fun ones too and a mystery with some depth.

[Ruxandra · Rating 5 out of 5]

Another amazing Lady Ellen Investigates story! These characters feel like my friends, I can’t get enough. Move over Hamilton— I can’t wait to see where Alex’s storyline goes.

[Cyn Texas · Rating 5 out of 5]

I love Kelly Mason's books!! Her Lady Ellen Investigates are my latest faves!! Wonderful author with great books!

[Elliemae · Rating 3 out of 5]

audiobook format

[Miss Sharon Burstow]

Excellent

Great series of books. With endearing characters and without giving too much away
a sinister underlying plot line. Looking forward to the next one.

[Tina · Rating 4 out of 5]

I am getting more into this series.

[Watergirl · Rating 3 out of 5]

Good addition to an engaging series. The grammar is really poor. Lady Ellen is supposed to correct Lottie's grammar but hers is atrocious for the elite classes. Editor needed.

[Tg · Rating 5 out of 5]

This truly is a great book, which isn’t surprising if you have read others in a terrific series to date. Thoroughly enjoyable and highly recommended.