The journey kicks off when the devoted caregivers of three charming pets—Chance, a spirited young American bulldog; Sassy, a comical Himalayan cat who truly embodies her name; and Shadow, a sage old golden retriever—must temporarily entrust their beloved animals to a friend residing hundreds of miles distant. However, after a few days, the anxious pets start to suspect that their family may be in distress, prompting them to embark on a quest to return home. During their remarkable expedition across the stunning and rugged Sierras, they face unanticipated challenges from humans, other animals, and the natural environment.