The Dunlap siblings must solve the mystery of a sick pony on Chincoteague Island in this second book of a chapter book series inspired by Marguerite Henry's Misty of Chincoteague.

There's a sick horse at Misty Inn! Something Buttercup is eating?or being fed?is making her ill. Can Willa and Ben solve this pony problem and help Buttercup feel healthy again?

Kristin Earhart is the author of many books for young readers, among them titles in the Stablemates, Big Apple Barn, and Magic School Bus chapter book series. A former children's book editor, she lives with her husband and son in Brooklyn, New York.