Flash is an installment in The Puppy Place series. Each book in the series focuses on a new puppy that the human protagonists, Charles and Lizzie Peterson, temporarily foster. Flash is a specific puppy with a unique personality, likely being very fast, energetic, or perhaps temporarily injured. The plot details the children's efforts to care for, train, and find a perfect, permanent loving home for the puppy, teaching readers about animal responsibility and the emotional challenges of fostering.