Christina, Grant, Mimi, and Papa visit Yellowstone National Park, where they meet Gunny, who has his great-great-grandfather's treasure map, and Molly Jane, who visits Yellowstone every year; the adults and kids are ready for some swirling hot springs, bubbling mud pots, and spewing geysers.

In 2008 South Side Chicago, ten-year-old Montgomery "Monty" Carver's hunt to find the origins of a mysterious golden key leads him to discover the rich history of his community.

The Alden children, isolated in a storm at a small bus station, are led into a mystery centering on a polluted river.

Nine-year-old Ella considers herself the official greeter, tour guide, and is generally in charge of 1106 Wildflower Place, but the elusive Robinsons who live on the top floor are a mystery--one which Ella is determined to solve, and bring the elderly couple into the community of the apartment building on Poppy Hill.

In this fifth installment in the New York Times bestselling series from Edgar Award winner James Ponti, the young group of spies take on New York City in another international adventure perfect for fans of Spy School and Mrs. Smith's Spy School for Girls. The City Spies head to the Big Apple when a credible threat is made to a young climate activist who is scheduled to speak in front of the upcoming United Nations General Assembly. With Rio acting...

The Aldens help out at a minor league stadium and investigate when it appears someone in the ballpark is stealing the home team pitcher's signals and relaying them to the batters of the other team.