Niles, an aging Yorkie, has led a pampered life with his two loving owners and knows nothing of death. When his new friend Nathaniel, an inquisitive fruit rat, shares the puzzling tale of a family burying a “sleeping” cat, Niles’s life begins to change. Another neighborhood critter, an eccentric possum called Leach, explains to the two befuddled creatures that the cat wasn’t simply sleeping—it was dead. 
 
Shaken by this revelation, Niles and Nathaniel decide they need to do something meaningful with their lives—but what? They resolve to venture outside Niles’s backyard, and with the help of Poppy, a friendly parrot, and guided by cryptic messages from a cat Niles encounters in his dreams, they begin to seek out answers.
 
Their travels take them from their own neighborhood through a canyon right to the edge of the ocean. Along the way, they encounter and benefit from the wisdom shared by others—the seagulls, dolphins, and a visionary gorilla—about the mysteries of life, and the grace that comes from living “well” unafraid of their own mortality.