Grump's Secret

This is a funny story about Sixteen year old Jeremy Bele's, whose family moves in with his estranged grandfather. They find the old man mean, rude, obnoxious, and cruel. It's only supposed to last the summer, but the old man's antics make life in his large home taxing. But one day the family discovers he has done a ninety degree turn in personality.
While his family is content with the doctor's explanation, Jeremy has his own opinion about the suddenly very silent man. Eventually, in a cry for help, gramps spills the beans to a secret so outlandish, the only one who will believe Jeremy's bizarre tale is the girl next door.
Studying what info he has, Jeremy is convinced the only way to find a solution is to go to the source. Besides, they might find treasure.