65 million years ago, a disastrous cataclysm eliminated 3/4 of all life on Earth. Overnight, the age of dinosaurs ended. The age of mammals had begun. But what if history had happened differently? What if the reptiles had survived to evolve into intelligent life?
In West of Eden, best-selling author Harry Harrison has created a rich, dramatic saga of a world where the descendants of the dinosaurs struggled with a clan of humans in a battle for survival. Here is the story of Kerrick, a young hunter who grows to manhood among the dinosaurs, escaping at last to rejoin his own kind. His knowledge of their strange customs makes him the humans' leader...and the dinosaurs' greatest enemy.

A new ice age threatens Earth. Facing extinction, the dinosaurs must employ their mastery of biology to reconquer human territory swiftly. Desperately, Kerrick launches an arduous quest to rally a final defense for humankind. With his beloved wife and young son, he heads north to the land of the whale hunters, east into the enemy's stronghold, and south to a fateful reckoning with destiny.

After Kerrick rescues his people from the warlike Yilane, they find a safe haven on an island and there begin to rebuild their shattered lives. But with fierce predators stalking the forests, how long can these unarmed human outcasts hope to survive? And, of course, Kerrick cannot forget Vainte, his implacable Yilane enemy. She's been cast out from her kind under sentence of death, but how long will her banishment last? For her strange attraction to Kerrick has turned into a hatred even more powerful than her instincts - an obsession that compels her to hunt down Kerrick and kill him.