Twelve-year-old Skip Chapman has a simple plan for his summer vacation; finish his treehouse. What Skip hadn't anticipated was a summer vacation crammed with excitement, mystery, and danger. His project suffered a setback almost immediately but is instrumental in uncovering a crime. Under suspicion is the carnie, Stan, who has suddenly become part of the family. Penny, the youngest member of the Chapman family, charms her way into a new friendship and impacts a family that is falling apart. From catching a dragonfly to entering a pet show, Penny manages to stumble into unique and perilous experiences as easily as it is for her to breathe.