Henry, Jessie, Violet, and Benny used to live alone in a boxcar. Now they have a home with their grandfather and are spending the summer in a lighthouse on the New England coast. Jessie sees a mysterious woman waling on the grounds of the lighthouse late at night. Watch, Jessie's dog, wakes up growling almost every evening--at midnight. And Henry finds a puzzling note in the sand.... Many more strange things will happen before the Boxcar Children can solve The Lighthouse Mystery.