In the nineteenth book of the A to Z Mysteries—an early chapter book mystery series featuring strong boy and girl characters—it's a bona fide mystery at Dink's school. Some sneaky soul has stolen the skeleton from the nurse's office! The principal promises free aquarium tickets to the savvy student sleuths who can track down poor Mr. Bones. Soon mysterious clues are showing up all over the school. It's up to Dink, Josh, and Ruth Rose to follow the clues and put those old bones to rest.