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...