Once Sue Hollister receives a "lucky penny" as a reward, the entire family takes up the fascinating hobby of coin collecting. Their interest in coins quickly mounts when, on a visit to their cousins, Teddy and Jean, the family car is buffeted by a small tornado. In the roots of a tree blown down by the twister, Pete finds an old metal box. In it is a rare Oak Tree shilling and on the coin-the figure of a bird and the letters, t-r-e-a-s-u-r-e! Is there a real treasure, and if so, where is it hidden? As the Hollisters eagerly try to answer these puzzling questions, a famous coin collection is stolen from the Crestwood museum. The thief has left just one small clue that is overlooked by the police, but not by Pam. With two exciting mysteries to solve, the children turn to their new friend, the forester, whose extensive knowledge of trees helps them to decipher the message and locate both the stolen coins and the hidden treasure. Join the Happy Hollisters and share in the adventure and fun they have discovering the secret of the lucky coins. Paperback; 170 pages with 20 illustrations.