A dark and absorbing thriller that leaves the series in its strongest position yet

There is something about the Icelandic landscape that lends itself to secrets. The Westfjords, with their mountains plunging into cold dark waters and their scattered communities clinging to the shoreline, have always felt like places where the past is never truly buried. In Satu Rämö’s The Secrets from the Deep, that observation moves from subtext to the very heart of the story.

Readers of the series will by now be familiar with the curious English retitling policy that has seen each instalment renamed from its original character-driven title. Hildur became The Clues in the Fjord, Rósa & Björk was rebranded The Grave in the Ice, and Jakob transformed into The Shadow of the Northern Lights. True to form, this fourth volume was originally published as Rakel—the name of Hildur’s mother—and it is her story that finally steps centre stage here.

It is a naming convention that continues to puzzle, shifting the focus from the personal to the atmospheric, though in this case the English title carries more weight than most of its predecessors. Rämö has always understood that the deepest secrets are not those hidden under the ice, but those buried within the family. More than any previous instalment, this is the book that finally confronts the damage left behind by Hildur’s family history.

The Secrets from the Deep Review: Dark Secrets in the Westfjords

The Secrets from the Deep opens in 2022 with Detective Hildur Rúnarsdóttir arriving home after catching waves in Hawaii to find life in Ísafjörður unexpectedly settled. Work on restoring her childhood property is moving forward and her Finnish colleague and protégé Jakob Johanson has now made Iceland his permanent base. The jumper-knitting biologist turned detective is no longer a visitor to the Westfjords but a permanent part of Hildur’s world. For a moment, it seems the trauma of the previous three books might finally be receding.

Rämö, however, is not one to leave her characters in peace for long.

The calm of the Westfjords is shattered by two seemingly unrelated events. First, the colossal Diamond Adventure of the Seas cruise ship arrives in the fjord, bringing with it an invasion of tourists and a bloodied, terrified young Venezuelan kitchen worker who stumbles down the gangplank, his face scarred, his silence absolute. Then, as labourers dig for a new septic tank in the grounds of Hildur’s home, they uncover human remains. Not one skeleton, but several, interred where they should never have been.

When bones are found in your own backyard, the investigation stops being professional and becomes personal. For Hildur, this is not just another case; it is an excavation of her own history.

Dual Timelines and Shattered Memories

Running parallel to the 2022 investigation is a 1995 timeline, where a young German woman arrives in the Westfjords seeking solitude and adventure, only to vanish without trace. Her disappearance was barely investigated at the time; the local police were preoccupied with another tragedy: the fatal car accident that claimed the lives of Hildur’s parents, Rakel and Rúnar. The link between the vanished tourist, the skeletons, and the circumstances of that “accident” forms the intricate puzzle that Hildur and Jakob must unpick.

Where the previous book, The Shadow of the Northern Lights, belonged very much to Jakob, this is unequivocally Hildur’s story, and that of her mother Rakel, whose life and death have been shrouded in rumour and half-truths across the series. A visit to an elderly family friend in residential care begins to unravel the carefully constructed version of Rakel that Hildur has carried with her. The resulting portrait is one of the most compelling in the series: neither victim nor villain, but a woman shaped by fear, compromise, and impossible choices.

Rämö has always written Hildur as a study in controlled intensity—tough, capable, emotionally restrained—and here that restraint is tested to breaking point as she confronts the reality of her father’s abuse, her mother’s complicity, and the fate of her sisters Rósa and Björk. The fractured relationship between the three sisters remains the emotional core of the series, and the scenes they share carry a raw, unflinching weight that elevates the novel far beyond standard police procedural fare.

Jakob, for his part, settles into a quieter but no less vital role. His biology background proves invaluable when the skeletons are exhumed, and his steady presence provides the ballast that prevents Hildur from capsizing entirely. Fans of his idiosyncratic knitwear-based problem solving will not be disappointed, though with his custody battle resolved and his future now firmly rooted in Iceland, he feels less like the outsider he was in The Clues in the Fjord and more like the foundation of this unlikely investigative unit.

A Layered Thriller with TV Potential

As ever with Rämö, the pacing is deliberate. This is not a novel that rushes towards its twists; rather, it allows tension to accumulate through small, telling details—a throwaway comment from a local fisherman, a faded photograph in Helga’s room, a memory that Hildur has spent decades suppressing. The dual-timeline structure works particularly well here, with the 1995 narrative gradually illuminating the 2022 investigation in ways that feel earned rather than engineered.

There are moments, particularly in the middle third, where the accumulation of interviews, reports, and procedural detail threatens to slow the narrative’s momentum. The Westfjords don’t give up their secrets easily, and Rämö makes her readers work for every revelation.

The arrival of the cruise ship becomes a prism through which to examine mass tourism, labour exploitation, and the fragility of small-town ecosystems when confronted by global capital. The folklore and local beliefs woven into the narrative are never treated as set dressing; they are the living, breathing context in which these characters understand their world.

The climax delivers both on the mystery front and the emotional one. Rämö draws together the disparate threads—the tourist, the cruise ship, the skeletons, and Rakel’s story—with her customary clarity, revealing truths that are satisfyingly complex rather than sensationally neat. Not every loose end is wrapped up, and deliberately so; this is, after all, a series, and there are clearly further revelations to come in the already confirmed fifth instalment, The Stranger from the Mountains.

The Secrets from the Deep is not without its imperfections. Some of the supporting characters remain frustratingly underdeveloped, and the cruise ship storyline occasionally relies on coincidences that feel less convincing than the novel’s otherwise meticulous plotting. But these are small flaws in what is otherwise the strongest entry in the series since the debut.

With a TV adaptation now in development, the Hildur phenomenon shows no sign of slowing. For readers who have followed Hildur from her first appearance in The Clues in the Fjord, this is the series at its most emotionally revealing, and arguably its most accomplished.

The Secrets from the Deep by Satu Rämö, translated by Kristian London, is published by Zaffre and out now.