The entire town of Yellow Sands is left puzzled by a mysterious fire.

"The Aldens are spending spring break on a beach, but they aren't just soaking up the sun. They're protecting an endangered species! Their job is to mark sea turtle nests so the eggs can be moved to a safe place to hatch, but someone is digging up the eggs without permission. Can the Boxcar Children figure out what's going on and help save the sea turtles?" --

The Aldens begin their adventure by making a home in a boxcar. Their goal is to stay together, and in the process they find a grandfather.