One spring evening, the town of Covenly gains three new residents, whose strangeness makes some of the other citizens uneasy. Hildegurp, Yuckmina, and Glubbifer set up shop, hoping for a fresh start and a new business: a pet store. Their first customer is nine-year-old Jessica Nibley, who has lost her pet goat and hopes the sisters can help track it down. But as they exit the shop, they discover a mangled note with missing pieces that suggests the sisters aren't welcome in Covenly. Now they have two mysteries to solve: a mysterious note and a missing goat. As they broom off to search for clues, they meet other Covenly residents.