June Andersen is professionally successful, but her personal life is marred by unhappiness. Unexpectedly, she is called to settle her great-aunt Ruby’s estate and determine the fate of Bluebird Books, the children’s bookstore Ruby founded in the 1940s. Amidst the store’s papers, June stumbles upon letters between her great-aunt and the late Margaret Wise Brown --- and steps into the pages of American literature.
Fleeing an East Coast life marred by tragedy, Ada Santorini takes up residence on houseboat number seven on Boat Street. She discovers a trunk left behind by Penny Wentworth, a young newlywed who lived on the boat half a century earlier. Ada longs to know her predecessor’s fate, but little suspects that Penny’s mysterious past and her own clouded future are destined to converge.