July 1939. War is on the horizon, but on Monk Island, Maine, life goes on as usual. As the daughter of a lobsterman, Ellie Ames’ future seems limited until a mysterious German couple comes off the ferry with their 19-year-old son. From the moment she meets Karl Brink, the two become inseparable, and not everyone approves because locals are suspicious of outsiders. Ellie ignores their scorn, however, and the secret she learns about Karl’s family makes her even more determined to be with him. The magical summer ends when the Brinks suddenly have to go home. And although Karl promises to return in the fall, by then Europe is at war. Two years pass, and Ellie has all but given up hope when she gets a letter in the mail that will change her life forever.