ISBN-13: 9780807553725 / Angielski / Miękka / 1990 / 128 str.
The Boxcar Children are spending the summer in a mobile home on the beach. One morning Benny finds a valuable gold locket in the sand and decides to try to find its owner. Soon, the kids are caught up in a puzzle that involves shadowy figures on the beach and the mysterious Miss Smith, who seems to be alone in the big Tower House nearby.