Exo

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.

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.

Author: Colin Brush
Publisher: Diversion Books
Published: 11/18/2025
Pages: 352
Binding Type: Paperback
Weight: 0.94lbs
Size: 9.00h x 6.00w x 0.88d
ISBN: 9798895150528


Review Citation(s):
Publishers Weekly 08/25/2025
Library Journal 09/01/2025 pg. 63
Booklist 10/09/2025

About the Author
Colin Brush was born in Scotland and reluctantly raised on the small Channel Island of Jersey. After a sojourn studying geology in Glasgow, he moved to London and consequently worked as a bookseller, stock controller, proofreader, copyeditor, quarterly zine publisher, catalog and advertising copywriter and, currently, a jacket copy writer at the UK's largest publisher. Over the last quarter century he has written the cover copy for well over 5,000 books. He lives with his partner and their two daughters on the southeastern coast of England, a few miles from Dungeness, the wave-battered and pebble-beached wilderness that is the inspiration for Exo.