When Adele walks her little brother Simon home from school he loses one more thing at every stop: his drawing of a cat at the grocer's shop, his books at the park, his crayons at the art museum, and more.
When Adele and Simon visit their Aunt Cecile in New York City, she takes them on a train trip around the United States; but from Boston to San Francisco to Washington, D.C., Simon keeps losing his belongings, despite his sister's reminders.