
Exo
A Novel
Diversion Publishing · Print & ebook · November 18, 2025
A debut sci-fi mystery set on an abandoned future Earth, featuring a twisty mystery straight out of a John le Carré novel, a group of larger-than-life characters who’d be at home in the work of John Scalzi, and a deeply weird and dangerous hyperdimensional entity to haunt the dreams of any reader of Kim Stanley Robinson.
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- Who it’s for
- A brisk, prestige-leaning blend of mystery, science, and alien contact.
- Genres
- Sci-Fi Crime, Apocalyptic & Post-Apocalyptic, Women Detectives
- Published
- Diversion Publishing, November 18, 2025
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For younger readers: Exo, Star Splitter, Alone Out Here
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A debut sci-fi mystery set on an abandoned future Earth, featuring a twisty mystery straight out of a John le Carré novel, a group of larger-than-life characters who’d be at home in the work of John Scalzi, and a deeply weird and dangerous hyperdimensional entity to haunt the dreams of any reader of Kim Stanley Robinson. Humanity is dying. Banished from the Earth, our descendants eke out lives in orbital habitats and moon colonies––and look with longing on our former home.
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But Earth is deadly. Over hundreds of years, its oceans have transformed into an annihilating liquid entity––the Caul. Every living creature approaching its shores is irresistibly compelled to enter. . . and is never seen again. Scientists, some of the few inhabitants left, work in facilities seeking to understand and stop the Caul. And scavenging the shores are the penitents—those who resist its siren lure. Among them is penitent Mae Jameson, an octogenarian former Service agent who arrived on Earth thirty years ago to find her lover. When she encounters Siofra, a mute girl, wandering alone by the shore and returns her home, they discover the girl's father, rogue scientist Carl Magellan, hanging from a noose. He's been murdered. Unwilling to leave the matter in the hands of the facility Carl abandoned years ago, Mae takes Carl’s journals—which detail his obsession with the Caul and its mysteries—and sets about investigating. In this page-turning, dual-timeline novel, both Mae and Carl's quests for the truth put them at the center of a dangerous conspiracy. Someone believes they can use the secret of the Caul to shape humanity's future, and they aren't afraid to kill to keep control of it.
What Lands
A brisk, prestige-leaning blend of mystery, science, and alien contact.
Come here for
- genre-blending sci-fi crime
- serious, layered momentum
Expect
- sustained narrative drive
- conversation-ready genre mix
Where it sits
| Sci-Fi Crime | 96% |
|---|---|
| Apocalyptic & Post-Apocalyptic | 60% |
| Women Detectives | 26% |
Percentages are BookFrontier’s reading of the book.
Publisher categories
- Women Detectives
- Apocalyptic & Post-Apocalyptic
- Sci-Fi Crime
- Authors
- Colin Brush
- Publisher
- Diversion Publishing
- Published
- November 18, 2025
- Format
- Print & ebook
- Reading lane
- Women Detectives