"Nine long months after being shut out of the pillow fort network for good, Maggie and Abby finally have a whole new mission to focus on--and this one starts with a return to the infamous Camp Cantaloupe. Abby needs this trip after a year of big, BIG changes back at home. But Abby knows that Maggie will never relax until they've solved the lingering puzzle left over from last summer: the mystery of the trap door in Camp Cantaloupe's historic Shipwreck...