Part one
Summary
Frank and Joe Hardy are on a trip to Arizona's magnificent Organ Pipe Cactus National Monument with father. There they meet their father's old friend Winston Grisham, or Grish, as he liked to be called. Grish takes the Hardy's on a tour showing them around the park. Frank spots big tire marks and questions Grish why there are big tire marks. Grish tell them that there are cactus thieves. So there is another case for the Hardy's to solve. Frank and Joe decide to help Grish. Grish does not agree at first, but afterwards hi agrees. Fenton Hardy invites Grish for dinner. The…