When Isaiah Edwards loses his will to live after a crippling logging accident, a letter to Walnut Grove from his worried wife, Grace, brings Charles and Laura back to the big woods to try to help their old friend.

Reverend Edward Danford, a preacher and "faith healer," comes to Walnut Grove with his fascinating concept of overcoming all physical adversities with pure faith in God. As his popularity increases, he decides to stay in town permanently.