Life is hard for the three Stone children. The death of their mother has left them bereft and grieving. Their father tries hard to make things better, but he is busy trying to keep their farm going. Even the land around them seems to have betrayed them: It is so barren that it is known as sour land.
Then Moses Waters comes to teach at the black school at Cedar Corners. Moses can hear things no one else can, like the sound of the grass and the earth humming together. More than anyone else, he seems to have a special understanding of the Stone family. Only Moses can help them out of their grief.
But a sour land grows sour people. There are some folks in town who don't approve of the friendship between the white Stone family and the new black teacher. And it looks like they will go to dangerous lengths to stop it.