After being abandoned in Golden Gate Park by owners who no longer want her, Dark must quickly learn how to take care of herself. Befriended by a racoon, Rattail, and Casablanca, another feral cat, Dark quickly learns her place in the park's hierarchy, and discovers who she can trust--the Warms (nice people who feed the ferals every day)--and who's to be avoided--the Cores (homeless kids who live in the park) and the Dangers (who include clueless humans who don't always consider their impact on the park and its social structure).

But when coyotes start invading the park and the streets immediately surrounding it, the stability of San Francisco and the park are threatened. Guided by the ghost stories and mysterious musings of a homeless woman and the determination of Jesse, a human sometimes-park resident, Dark must make difficult decisions about friendship, loyalty, and the meaning of survival.