The Only One Left by Riley Sager delivers exactly what fans of the author expect: a propulsive, gothic-tinged mystery that weaponises the past. Published in 2023, the novel takes a premise ripped from true crime folklore and builds something slick and genuinely unsettling around it. The result is a book that earns its place in the crowded field of domestic horror thrillers, even if it doesn't always reach the heights it aims for.
What the book is about
The setup borrows from the legend of Lizzie Borden. In 1929, seventeen-year-old Lenora Hope is the only survivor after her entire family is found dead in their seaside mansion. The town assumes she did it. Decades later, in 1983, nurse Kit McDeere arrives at Hope's Cliff, the crumbling estate, to care for the now-elderly Lenora. Lenora can't speak but she can type, and she wants Kit to help her tell her story. What follows is a dual timeline thriller that alternates between Kit's present investigation and Lenora's typed confessions from the night everything went wrong.
Sager builds the structure carefully. Each revelation from Lenora's past lands at exactly the right moment to nudge the present-day plot forward. It's a clockwork arrangement, and for most of the novel it ticks along without skipping a beat.
Where the gothic atmosphere lands
Hope's Cliff is a setting Sager clearly relishes. The house sits on a literal cliff edge, rooms eaten by damp, a section already swallowed by the sea. It's the kind of place where the architecture does half the work, and Sager lets it. The ocean is a constant presence, audible in almost every scene, which keeps a low dread humming underneath even the quieter chapters. Fans of haunted-house adjacent fiction will recognise the pleasure of a location that feels actively malevolent without anything supernatural being confirmed.
The atmosphere reminded me, at points, of the oppressive coastal unease in The Haar by David Sodergren, where the sea itself becomes a kind of antagonist. Sager isn't doing folk horror here, but the elemental menace of water and eroding ground is put to similar use.
Kit as a protagonist
Kit arrives with her own baggage. She was blamed for a patient's death at her previous post, a scandal that hasn't fully resolved by the time the story begins. It's a smart structural choice: a protagonist already compromised, already disbelieved, already carrying the weight of an accusation she may or may not deserve. It mirrors Lenora's situation directly. Both women are suspected killers. Both are either innocent or lying. This doubling is the book's strongest idea.
The problem is that Kit sometimes reads as a function of the plot rather than a person inside it. Her instincts exist to move the mystery forward, not because the novel is particularly interested in who she is off the page. That's a common issue in thriller fiction, and Sager doesn't solve it here. Still, Kit's emotional investment in Lenora's story feels genuine enough to carry the reader through the slower middle sections.
The twists: earned or engineered?
Riley Sager has built a reputation on the late-act reversal, and The Only One Left doesn't break with tradition. There are at least 3 significant pivots in the final quarter. Whether they feel earned depends on how closely you're paying attention to the earlier chapters. Sager is meticulous about hiding information in plain sight, so a re-read does reward close attention. The first major reversal is legitimately surprising. The second is somewhat telegraphed if you've read enough of the genre. The third lands with real force.
What separates this from lesser thriller fiction is that the twists change the emotional stakes, not just the plot mechanics. When the truth about 1929 emerges, it doesn't just answer a whodunnit question. It reframes the entire relationship between Kit and Lenora, and that's where The Only One Left earns its keep as something more than a puzzle box.
Comparisons and context
Sager's work sits in the space between mainstream thriller and horror. It's closer to the domestic unease end of the dial than to outright terror. Readers who arrived at horror via gothic fiction or who enjoy the dread-laden atmosphere of something like The Southern Book Club's Guide to Slaying Vampires by Grady Hendrix will likely find the tone familiar: genre pleasures, female protagonists navigating dangerous environments, horror with a social dimension.
The Only One Left is not Sager's most ambitious book. Penguin Random House's official listing for the novel sits it firmly in thriller-horror crossover territory, and that's accurate. If you go in expecting literary horror, you'll be disappointed. If you go in expecting a well-constructed, atmosphere-heavy mystery with a genuinely moving emotional core, you won't.
Final verdict
The Only One Left by Riley Sager is a confident, readable entry in the gothic thriller genre. The dual timeline works. The setting is exceptional. The twist structure is more sophisticated than it first appears. Kit's thinness as a character is a real limitation, but Lenora compensates: she's the book's heart, and Sager writes her with genuine compassion. Not every reader will forgive the engineered quality of the plotting, but those willing to meet the novel on its own terms will find a late-night read that delivers exactly what it promises.
Four out of five. Recommended for fans of dark, coastal atmosphere, historical mystery, and morally complex narrators who may or may not be telling the full truth.