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The Kernoz Oath: A Brittany Island Mystery
Maëlle Kerneur, fifty-four, out of work and recently divorced, returns in March to the island of Kernoz to empty her dead grandmother's house. She left at eighteen and has not been back in thirty-six years.
Six days after she lands, the island's retired schoolmaster is found dead below the bunker at Pointe Noire. The gendarmerie rules it a fall. But the cardboard folder he had been carrying for forty years has gone, and in her grandmother's bureau Maëlle finds a letter from him, opened, addressed to a woman two months dead, naming an appointment at the mairie.
He had spent his life on one question. In August 1984, Erwan Le Bris, the mayor's eleven-year-old son, was said to have drowned at Pointe Noire. His body was never recovered. Maëlle, Yann, Bastien and Morgane were with him that summer, and the five of them had been hiding an injured man in the bunker for eleven days.
The four survivors, who have not spoken to one another in forty years, begin to reconstruct what happened, from ticket counterfoils, council minutes, a grave lease in Savenay and a boy's science exercise book.
In August, four thousand holidaymakers arrive, an exhibition of three thousand old photographs opens in the village hall, and a woman who has been on this island thirty-seven days in forty years drowns at the north slipway.
Translated from the French. A slow-burn island mystery for readers of Peter May, Ann Cleeves and Jean-Luc Bannalec.
Six days after she lands, the island's retired schoolmaster is found dead below the bunker at Pointe Noire. The gendarmerie rules it a fall. But the cardboard folder he had been carrying for forty years has gone, and in her grandmother's bureau Maëlle finds a letter from him, opened, addressed to a woman two months dead, naming an appointment at the mairie.
He had spent his life on one question. In August 1984, Erwan Le Bris, the mayor's eleven-year-old son, was said to have drowned at Pointe Noire. His body was never recovered. Maëlle, Yann, Bastien and Morgane were with him that summer, and the five of them had been hiding an injured man in the bunker for eleven days.
The four survivors, who have not spoken to one another in forty years, begin to reconstruct what happened, from ticket counterfoils, council minutes, a grave lease in Savenay and a boy's science exercise book.
In August, four thousand holidaymakers arrive, an exhibition of three thousand old photographs opens in the village hall, and a woman who has been on this island thirty-seven days in forty years drowns at the north slipway.
Translated from the French. A slow-burn island mystery for readers of Peter May, Ann Cleeves and Jean-Luc Bannalec.
- GenresMystery
579 pages, Kindle Edition
Published September 12, 2026
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Displaying 1 - 3 of 3 reviews
September 25, 2026
A Slow-Burning Mystery Built on Memory, Secrets, and the Past
I read The Kernoz Oath: A Brittany Island Mystery as part of the Eastside Bookclub, and I found it to be the kind of mystery that rewards patience. Rather than relying on constant action, Gabriel Mongin builds the story gradually, allowing the island, its history, and its characters to become increasingly important as the mystery unfolds.
What stood out to me most was the way the past continually intrudes on the present. Maëlle's return to Kernoz after thirty-six years immediately creates a strong sense of unfinished business, and the death of the retired schoolmaster opens the door to questions surrounding Erwan Le Bris's disappearance in 1984. The connection between the two events gives the story an intriguing layered structure.
I particularly enjoyed the use of seemingly ordinary pieces of evidence, old photographs, ticket counterfoils, council minutes, a grave lease, and a child's exercise book, to gradually reconstruct something that happened decades earlier. It gives the investigation a more grounded feeling and makes the reader pay attention to details that might initially seem insignificant.
The island setting also adds considerably to the atmosphere. Kernoz feels like a place where memories don't disappear easily, and the arrival of thousands of holidaymakers alongside the exhibition of old photographs creates an interesting contrast between the island's present and its buried history.
For our Eastside Bookclub discussion, I thought the book offered plenty to consider, particularly the effects of unresolved guilt, childhood memories, long-held secrets, and the ways people remember the same event differently after decades have passed.
Overall, The Kernoz Oath is a character-driven, atmospheric mystery that takes its time revealing its secrets. Readers who enjoy slow-burn investigations, isolated settings, historical mysteries, and stories where the past gradually catches up with the present may find plenty to appreciate here.
A thoughtful mystery with an evocative setting and an intriguing emphasis on memory, evidence, and the secrets people carry for decades.
I read The Kernoz Oath: A Brittany Island Mystery as part of the Eastside Bookclub, and I found it to be the kind of mystery that rewards patience. Rather than relying on constant action, Gabriel Mongin builds the story gradually, allowing the island, its history, and its characters to become increasingly important as the mystery unfolds.
What stood out to me most was the way the past continually intrudes on the present. Maëlle's return to Kernoz after thirty-six years immediately creates a strong sense of unfinished business, and the death of the retired schoolmaster opens the door to questions surrounding Erwan Le Bris's disappearance in 1984. The connection between the two events gives the story an intriguing layered structure.
I particularly enjoyed the use of seemingly ordinary pieces of evidence, old photographs, ticket counterfoils, council minutes, a grave lease, and a child's exercise book, to gradually reconstruct something that happened decades earlier. It gives the investigation a more grounded feeling and makes the reader pay attention to details that might initially seem insignificant.
The island setting also adds considerably to the atmosphere. Kernoz feels like a place where memories don't disappear easily, and the arrival of thousands of holidaymakers alongside the exhibition of old photographs creates an interesting contrast between the island's present and its buried history.
For our Eastside Bookclub discussion, I thought the book offered plenty to consider, particularly the effects of unresolved guilt, childhood memories, long-held secrets, and the ways people remember the same event differently after decades have passed.
Overall, The Kernoz Oath is a character-driven, atmospheric mystery that takes its time revealing its secrets. Readers who enjoy slow-burn investigations, isolated settings, historical mysteries, and stories where the past gradually catches up with the present may find plenty to appreciate here.
A thoughtful mystery with an evocative setting and an intriguing emphasis on memory, evidence, and the secrets people carry for decades.
November 7, 2026
An island of 700 people
We never said anything to each other. Never. Not once in forty years
It's an island.
It's an illness.
Freakin author! What was that non ending? So what happened!
579 pages
Five friends one goes missing and is presumed to have drowned. Forty years later the four try to solve what happened.
It shouldn't take 579 pages to tell the story.
I'm the man in the box, buried in my shit
Won't you come and save me, save me?
Feed my eyes, can you sew them shut?
Jesus Christ, deny your maker
Who the fuck was the man in the box?! Freakin' author!
Goodreads giveaway
We never said anything to each other. Never. Not once in forty years
It's an island.
It's an illness.
Freakin author! What was that non ending? So what happened!
579 pages
Five friends one goes missing and is presumed to have drowned. Forty years later the four try to solve what happened.
It shouldn't take 579 pages to tell the story.
I'm the man in the box, buried in my shit
Won't you come and save me, save me?
Feed my eyes, can you sew them shut?
Jesus Christ, deny your maker
Who the fuck was the man in the box?! Freakin' author!
Goodreads giveaway
November 4, 2026
I won this book in a goodreads drawing.
I really thought this would be a cozy, but it's actually a psychological thriller.
After 35 years, a denizen of the Brittany Isles comes back home to clean things up after inheriting a house. There's a host of unpleasantness going back to a mysterious night in 1984. The Brittany Islands are an uneasy mix of British and French ancestry, and that is very plain.
I think a cozy might have been a better choice.
I really thought this would be a cozy, but it's actually a psychological thriller.
After 35 years, a denizen of the Brittany Isles comes back home to clean things up after inheriting a house. There's a host of unpleasantness going back to a mysterious night in 1984. The Brittany Islands are an uneasy mix of British and French ancestry, and that is very plain.
I think a cozy might have been a better choice.
Displaying 1 - 3 of 3 reviews