All Nessa knew was that Cats and Dogs were different.
Always had been. Always would be.

Generations in the future, our world has been changed irrevocably by an unspeakable disaster. In this bleak landscape a cat named Nessa has been exiled from her community during a violent outbreak with a group of Dogs. But when Nessa meets a fellow exile, a Dog named Farral, these unlikely companions set off to uncover the truth about their ancestry. Could Cats and Dogs have more in common than they have been taught to believe? Award-winning author Kate Thompson has crafted a brilliant page-turner in which readers will ultimately discover the secrets of a society's origins and the truth about what really happened in a genetic lab called Fourth World.