The Unknown.jpg
The Unknown.jpg

The Unknown by Riley Sager

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Hardcover:

THE INSTANT #1 NEW YORK TIMES BESTSELLER

The first edition of this stunning hardcover features designed endpapers, a foil-stamped case, hued edges, and a shimmery jacket!

In 1926, five women disappeared from a remote island in Vermont. Now, one hundred years later, it’s happening again.

Struggling actress Marin Keane is shocked when she lands a role in a major motion picture about the unsolved mystery of New Avalon, an island on sprawling Lake Faraday in Vermont. She’s even more surprised when she learns that the role requires a weeklong research trip to that very spot.

Because New Avalon isn’t your ordinary island. A century ago, it was a commune for spiritual mediums—until they all vanished in 1926. The only trace of them was five dresses hanging from the branches of an old oak tree in the middle of the island, one for each missing woman. Some locals say they simply left. Others think they were murdered. But the prevailing opinion, thanks to a diary left behind by one of the vanished, a young woman named Daisy Rue, is that a séance gone wrong conjured something supernatural that took them all one by one.

Not long after arriving, Marin and her castmates, including legendary actress Violet Wright and white-hot director Ronan Peters, begin to realize all is not right with New Avalon. They hear strange noises in the night and notice mysterious symbols left behind by the island's previous occupants. And after a sudden health emergency leaves Marin, Ronan, and the other actors stranded on the island, the disappearances begin again.

Is it the work of someone trying to derail the movie? Or is the island’s alleged supernatural past catching up with the present? As fear and suspicion mount, Marin turns to Daisy’s diary, hoping it holds the key to figuring out what really happened to the women of New Avalon—and how to keep the island’s terrible history from repeating itself.

THE INSTANT #1 NEW YORK TIMES BESTSELLER

The first edition of this stunning hardcover features designed endpapers, a foil-stamped case, hued edges, and a shimmery jacket!

In 1926, five women disappeared from a remote island in Vermont. Now, one hundred years later, it’s happening again.

Struggling actress Marin Keane is shocked when she lands a role in a major motion picture about the unsolved mystery of New Avalon, an island on sprawling Lake Faraday in Vermont. She’s even more surprised when she learns that the role requires a weeklong research trip to that very spot.

Because New Avalon isn’t your ordinary island. A century ago, it was a commune for spiritual mediums—until they all vanished in 1926. The only trace of them was five dresses hanging from the branches of an old oak tree in the middle of the island, one for each missing woman. Some locals say they simply left. Others think they were murdered. But the prevailing opinion, thanks to a diary left behind by one of the vanished, a young woman named Daisy Rue, is that a séance gone wrong conjured something supernatural that took them all one by one.

Not long after arriving, Marin and her castmates, including legendary actress Violet Wright and white-hot director Ronan Peters, begin to realize all is not right with New Avalon. They hear strange noises in the night and notice mysterious symbols left behind by the island's previous occupants. And after a sudden health emergency leaves Marin, Ronan, and the other actors stranded on the island, the disappearances begin again.

Is it the work of someone trying to derail the movie? Or is the island’s alleged supernatural past catching up with the present? As fear and suspicion mount, Marin turns to Daisy’s diary, hoping it holds the key to figuring out what really happened to the women of New Avalon—and how to keep the island’s terrible history from repeating itself.

  • Publisher: Dutton

    Title: The Unknown

    Author: Riley Sager

    On Sale Date: August 4, 2026

    ISBN 13: 979-8217044092

    Format: Hardcover

    Retail Price: $32.00

    BISAC: FICTION / Thrillers / Suspense

    Page Count: 368

    Dimensions: 6.38 x 1.23 x 9.31 inches

  • Riley Sager writes the kind of thriller you finish in a single anxious sitting. The New York Times bestselling author of Final Girls, The Only One Left, and Middle of the Night, Sager has built a reputation as one of suspense fiction's most reliable page-turners, blending classic thriller mechanics with a taste for the uncanny. A native of Pennsylvania, he now lives in Princeton, New Jersey.

  • Critics and fellow bestselling authors are calling it atmospheric, eerie, and unputdownable:

    • "Sager spruces up well-worn genre tropes with aplomb." —Publishers Weekly

    • "Atmospheric, eerie, and exactly the kind of unputdownable summer thriller." —Scary Mommy

    • "A shoe-in for one of our most anticipated reads of the year." —Fangoria

    • "The Unknown is more than worth the wait." —Parade

This book is for you if

  • You want a ghost story with real bite—part supernatural chiller, part locked-island mystery

  • You're drawn to dual-timeline novels where a century-old diary unravels a modern-day nightmare

  • You loved the eerie, character-driven suspense of Sager's earlier hits like Final Girls or The Only One Left

  • You like your thrillers with a Hollywood twist—this one unfolds behind the scenes of a cursed movie shoot

  • You're ready for the "unputdownable" beach read everyone will be talking about this fall

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