Five dresses hang from the oak tree at the center of New Avalon, one for each of the five women who vanished from the island in 1926, and they're the only trace the women left. New Avalon sits on sprawling Lake Faraday in Vermont, and a century ago it was a commune for spiritual mediums. A century later, Riley Sager sends a film crew there to shoot a movie about that same unsolved case, and puts struggling actress Marin Keane in the middle of it. The setup for The Unknown does what Sager's strongest books do: it takes an unsolved crime, builds a fresh one directly on top of it, and dares you to keep the two apart. It's a gothic thriller with a horror engine, the historical case and the present-day one trading suspects almost from the first night on the island.
The research trip is Sager's excuse to drop present-day characters straight into a hundred-year-old mystery. Marin's chapters run alongside pages from the diary of Daisy Rue, one of the vanished mediums, and the two timelines needle each other more than they simply alternate. Daisy's account of a séance gone wrong reads like local legend right up until the present-day cast starts hearing strange noises at night and finding symbols the island's old residents left behind. Sager holds the choice between folklore and coincidence open for a long stretch, and that patience gives the early chapters their held breath.
Then a health emergency strands the whole production on New Avalon, including veteran actress Violet Wright and hotshot director Ronan Peters, and the book tightens into a locked-room mystery where everyone on set is a suspect and a possible victim in the same breath. Noises turn up at night that nobody will claim. Someone is either restaging 1926 to sabotage the movie, or 1926 never actually stopped happening. Sager plays both readings straight for most of the book, which is the harder trick to pull off: a weaker novel tips its hand early with a raised eyebrow or a suspiciously well-timed close-up. This one keeps you watching the whole cast, because nobody is safely out of the frame.
The diary is the novel's best device, and by the middle stretch, also its biggest drag. Once the clue-then-echo pattern sets in, a run of chapters mostly restates it: another detail surfaces from 1926, a matching detail turns up in the present, another castmate insists it's coincidence. The dread survives the repetition. The momentum doesn't, and the book loses some of the grip it built in the first half.
Why you should read
- Readers of Sager's earlier isolated-setting thrillers
- Fans of dual-timeline mysteries built around a diary
- Anyone who likes supernatural threat left genuinely ambiguous
- Readers who enjoy a locked-room cast full of suspects
What to expect
- Alternating present-day and 1926 diary chapters
- Slow-building dread that pays off late
- A saggy middle stretch before the final act tightens
- An ensemble cast who are suspects and victims at once
- Ambiguity between sabotage and the supernatural held late
Sager keeps both explanations, sabotage and something the séance let in, alive long enough that either answer would cost something. That's the pleasure of The Unknown: an island legend that refuses to stay in 1926, and a writer willing to make you sit with the question before she answers it.
