When Tang Kelly's hermit-like grandfather goes missing, she turns to Kit Andrews and Swifty Olson of Rocky Mountain Searchers to find him.

Tang has not seen her grandfather in ten years, and her only connection has been a yearly birthday card sent from a post office in Woods Landing, Wyoming.

Kit and Swifty begin the search for Tang's grandfather and eventually find his remote, off-the-grid cabin high in the foothills of Wyoming. The grandfather is nowhere to be found, but they discover that six framed illustrated letters from the legendary western artist Charles M. Russell to his old cowboy pal, Kelly's great-grandfather, are missing.

Kit and Swifty initiate a search, bringing them in contact with the local law enforcement officials and numerous colorful characters who seem to flourish in this wild and remote area of Wyoming. The disappearance of Kelly's grandfather becomes a search for him and the missing Russell-illustrated letters. The search leads both Kit and Swifty into a dangerous confrontation with the kidnappers and thieves who are willing to commit murder to protect their secrets and the Russell letters.