The Book of Elsewhere is a fantasy novel co-written by Keanu Reeves and acclaimed British author China Miéville, published by Del Rey (Random House). A New York Times Bestseller, the book follows an immortal warrior known only as "B" who has witnessed the rise and fall of civilizations across millennia. When B enlists the help of a U.S. black-ops team in a desperate bid to finally achieve mortality, the unexpected resurrection of a fallen soldier reveals a mysterious force of equal power — setting the stage for a collision between ancient myth and modern warfare.

Expanding on the world of Reeves' BRZRKR comic book series, the novel blends visceral action with philosophical meditations on mortality, time, and what it means to be human. It has been praised as "action-packed and profoundly stylish" by the Los Angeles Times, and hailed as "an exceptionally innovative collaboration" by William Gibson.

The paperback edition runs 352 pages and is also available as an audiobook narrated by Reeves and Miéville themselves. ISBN: 9780593446607.