Dominguita is ready for another big adventure—and figures that her beloved library is a great place to try to find one! After Dominguita finds an old map in the back of a copy of Treasure Island, she is excited to see a big X on the map. Because everyone knows that X marks the spot for treasure! When Dom shows her friends Pancho and Steph, they don’t think the map is real. But after a little investigating, they discover there’s real treasure at stake! And there are a few other people who want that treasure too. Can Dom and her friends figure out a way to return the special treasure to one of their favorite people before it falls into the wrong hands?