"The S. P. Mystery" by Harriet Pyne Grove is a novel likely written in the early 20th century. The story centers around young girls who form a secret club filled with excitement, mystery, and adventure. Main character Jean Gordon is eager to transform the attic into a club room where she and her friends can participate in activities that blend fun with a spirit of exploration and camaraderie. The opening of the book introduces us to Jean as she rushes home with a vibrant enthusiasm for starting the club. She quickly seeks her mother's approval to use the attic for their gathering space and eagerly contacts her friends to share the news. The atmosphere is light and energetic as her friends gather to discuss their plans, and the idea of forming a secret society emerges when they realize the boys from their school have established one called the "Black Wizards." As the girls brainstorm names and activities for their own club, they settle on the moniker "Stealthy Prowlers," igniting a sense of adventure that promises to lead them into both fun and unusual challenges as they navigate the dynamics of friendship and curiosity. (This is an automatically generated summary.)