Maynard Olms is an eighty-year-old bachelor who lives in a three-room house with his wolf-dog, Duke, in the Ozark Mountains of southern Missouri. John and Marcella Washburn and their two children, Kelsey and Andrew, live on one end of Coon Hollow Road. Maynard and Duke live on the other.

It is the summer of 1988, "the nation's worst drought in 50 years," declares the July 4, 1988, issue of Time Magazine. Cattle are starving as Missouri pastures shrivel and die in the heat. Gardens yield no vegetables for canning and freezing. Orchard trees produce only nubbins of fruit. Apprehension seeps into the already-impoverished community.

On the first day of seventh grade, Kelsey Washburn comes home and tells her parents about her new friend, Ava McKittrick, who has just moved into their rural neighborhood from Arkansas. Motherless Ava, who lives with her father, Ben McKittrick, is a child prodigy in math and science.

A relationship blossoms between elderly Maynard and the two teenage girls, Kelsey and Ava. The girls carry supper to Maynard two nights a week. They stack his firewood, listen to his harmonica, and soak up the wisdom of his yarns.

The girls confide in Maynard, telling him about their dreams of college and hoped-for careers as a scientist and a veterinarian.

Maynard, who lives like a pauper, actually has a fortune hidden on his Missouri property. When Maynard dies, his Last Will and Testament directs that his money be distributed to Kelsey and Ava, to be used for their college educations, "if they can find it."

But Maynard's evil nephew, Clayton Olms, also has his sights set on finding Maynard's money and shows up on Coon Hollow Road at the most inopportune time.

It's a winner-takes-all treasure hunt between two teenage girls and Clayton Olms, a convicted criminal wielding a gun! Ultimately, Duke, Maynard's beautiful wolf-dog determines who finds the hidden treasure.