The plan was to have a quiet Christmas with extended family and NO mystery or adventure. But things rarely go as planned when the Double Cousins are involved. After finding an old diary under a loose floorboard, the Double Cousins uncover a slew of new questions in their latest mystery at the Old Sawmill Guest Ranch in Nemo, South Dakota. What happened to Sophia, the diary's owner? Where was the mysterious gold coin mentioned in another found journal? Could all their discoveries be clues to help answer the historic Black Hills puzzle and reveal where Custer hid his last payroll? Will the Double Cousins be able to answer all these questions and more and bring closure to a long-gone and far away family? With only a few days to their vacation and the threat of snow, the Double Cousins race against the clock in their most recent mystery.