In 1962, eight-year-old Ethan and his mother rescue a Golden Retriever puppy from a hot car. Despite the reservations of Ethan's father, the family adopts the pup they name Bailey. The two are inseparable during Ethan's childhood and teen years, but when he goes to college he has to leave Bailey at home. While Ethan is away at school, the aging dog becomes sick, and Ethan makes it to the veterinarian just in time for their final goodbye. Bailey is reborn in the body of Ellie, a German Shepherd K-9 first responder with the Chicago Police Department. Bailey continues to return in other reincarnations, and though he is unsure why his soul keeps returning for new adventures, he will discover that the purpose of his many lifetimes is more crucial to his boy than he could have ever imagined.