Plague riders

Fourteen-year-old Shep Greenfield rides his horse between the makeshift colonies along the Wisconsin River delivering homemade medicine to people infected with nightpox, and while trading meds for much needed grains, he finds evidence that suggests his missing parents may be alive in a distant settlement called Dusty Hollow, a disease-ridden settlement that is about to be burned down, and Shep must act quickly to find his parents.