"It's the 1920s. In the new Rocky Mountain National Park, two visitors are found dead-one hanged, perhaps by accident, one poisoned-Two small, cloaked figures have been adding white rocks to Flattop Mountain's ancient stone medicine circle. Where do the rocks come from? The ranger is going to have help untangling the puzzles: his glamorous friend, Vi Coteau, informs him that she's coming from Denver to go backcountry camping with him as he looks for the source of the rocks. Whether he wants her to or not"--.