Henry, Jessie, Violet, and Benny once lived on their own in a boxcar ... When the Aldens take a summer trip to the New England coast, they have a fun place to stay - a lighthouse! But strange things happen after it gets dark: an unknown woman is seen walking around, and Watch, the Aldens' dog, wakes up growling late at night. Can the Boxcar children shed light on a seaside mystery?
