During the 1920s, Billy, Finn, and Dannie, living in a railroad workers camp in the Cascade Mountains, encounter Finn's air show pilot uncle, endure a troublemaking new boy, and stand up to smugglers.
Upon leaving an oppressive summer camp, twelve-year-old Margaret Rose Kane spearheads a campaign to preserve three unique towers her grand uncles have been building in their back yard for over forty years.
Younguncle arrives in the middle of the Indian monsoon season and provides a group of bored children with clever, unexpected solutions to a variety of problems.
