Pirate Treasure of the Onyx Dragon

Your kooky Aunt Lydia warns you and your sister not to dig around into family secrets while you spend the summer at her spooky old house on San Juan Island in the Pacific Northwest. But you and your sister Hannah are born adventurers who spend your school year on an archaeological dig in Egypt. It's impossible to stay from away clues that might lead you to the Onyx Dragon, a sunken ship somewhere nearby. You are certain the ship contains the answer to your family mystery—and a rich pirate's treasure!