From bestselling author David Quammen, a fascinating scientific detective story about how a transmissible cancer first discovered in Tasmanian devils is connected to the discovery that cancer in humans can be treated as a chronic illness, not a fatal one—a radically new approach that promises not only survival but a better quality of life.

In The Devil You Don’t Know David Quammen introduces us to the revolutionary new field of evolutionary oncology, which reframes cancer as an evolutionary process, arguing that tumors adapt, compete, and survive through natural selection—and that understanding this is key to better treatment.

Using the dramatic case of a contagious cancer in Tasmanian devils as an example, Quammen explores how cancer evolves within and sometimes between bodies, how cancer in certain animals teaches us about cancer in humans, and how this evolutionary model is reshaping oncology, leading to new therapies that treat cancer as a chronic disease, rather than a terminal diagnosis.

With his trademark talent for explaining complex scientific stories, Quammen puts the scientists and researchers at the center of the narrative—some of whom have themselves been affected by cancer, making their work all the more urgent. We see how scientific breakthroughs are in fact based on years of careful research and innovative thinking, and how one generation of scientists builds on the work of the one that came before it.

Blending narrative, science, history, and field reporting, The Devil You Don’t Know contends that future treatments may depend less on total eradication and more on managing cancer as a dynamic biological system, with hopeful new outcomes for cancer patients.