The story of "Schoolhouse Mystery" revolves around a character named Henry James Alden, who is part of a family of adventurers known for their curiosity and problem-solving skills. The narrative showcases an intriguing mystery that unfolds in a schoolhouse, leading the Alden children on a thrilling journey to uncover the truth. Their teamwork and cleverness play key roles in resolving the challenges they face.

Throughout the book, the dynamic among the Alden siblings is highlighted, revealing their unique strengths and deep bond. Additionally, the mention of James Henry Alden emphasizes the connection to family heritage, suggesting a legacy of exploration and inquiry that defines their adventures. The Alden children exemplify resilience and bravery as they confront the unknown, making "Schoolhouse Mystery" an engaging tale for young readers.