> At a Glance
> – Riley Sager’s 10th novel The Unknown arrives August 4, 2026
> – The thriller links five 1926 disappearances to present-day vanishings on a Vermont island
> – Sager calls it his “version of The Eras Tour” by weaving in nods to all nine prior books
> > Why it matters: Long-time fans get Easter eggs, while newcomers enjoy a self-contained, twist-heavy mystery
Riley Sager is celebrating a decade of bestsellers with a milestone release that bridges past and present. The Unknown, his 10th suspense novel, pairs a century-old mystery with a modern film shoot gone terrifyingly wrong.
The Premise
In 1926, five female spiritualists vanished from the commune on New Avalon Island, leaving only their dresses dangling from an oak. One hundred years later, history repeats itself when an actress and her crew arrive to shoot a movie about the cold case.
Struggling actress Marin Keane lands the role of a lifetime, but production requires an on-location retreat to the now-infamous island. Joined by veteran star Violet Wright and buzz-worthy director Ronan Peters, Marin hopes the project will revive her career-until castmates start disappearing.
What Sets It Apart
Sager crafted the novel as both a standalone story and a love letter to loyal readers.
- New characters and setting make it accessible to first-time fans
- Hidden references to Lock Every Door, With a Vengeance, and seven other titles reward longtime followers
- Dual timelines amplify tension as past diary entries foreshadow present danger
The author explains his approach:
> “Because it’s my tenth book, I wanted to mark the occasion by touching upon all my previous ones, either through plot, theme, tone or outright references to earlier books.”
Key Takeaways
- Release date: The Unknown publishes August 4, 2026, and is available for preorder now
- Structure: Stand-alone thriller that also functions as a retrospective of Sager’s catalog
- Next up: The writer has already begun his 11th book, teasing, “And so it begins again…”
With its cinematic setup and layered nods to the author’s earlier hits, The Unknown promises a summer 2026 page-turner for casual mystery lovers and Sager completists alike.
