Join the Boxcar Children for a thrilling adventure high up in the rocky peaks. When a sudden rockslide leaves Henry, Jessie, Violet, and Benny Alden stranded on Old Flat Top mountain, they have to figure out how to survive while waiting for a rescue team. But being stuck on a mountain is not completely bad news. As the four brave siblings explore their surroundings, they stumble upon a secret, hidden cave that has just opened up in the rocks. Inside, they find clues leading to a legendary treasure that rightfully belongs to an elderly Native American woman. You will be on the edge of your seat as you help the Aldens navigate the dangerous terrain. Grab your climbing gear and get ready to solve an incredible mystery that connects the rugged mountain to a long lost piece of history.