Twelve-year-old Lizzie Durango and her dad have always had a zoo to call their home. Lizzie spends her days watching the animals and taking note of their various behaviours. Though the zoo makes for a unique home, it's a hard place for Lizzie to make lasting friends. But all this changes one afternoon when she finds Tyler Briggs, a runaway who has secretly made the zoo his makeshift home. The two become friends and, just as quickly, stumble into a covert investigation involving the zoo wolves who are suddenly dying. Little do they know, this mystery will draw them into a high-stakes historical adventure involving the legend of John Muir as they try to navigate safely while lost in Yosemite National Park.