Penny Warner 
Mystery of the Pirate’s Treasure [PDF ebook] 

Readers will have tons of fun creating the codes right along with the characters in this interactive series. Cody, Quinn, Luke, and M.E. love playing around with codes. In fact, they love codes so much they have their own club, with a secret hideout and passwords that change every day. On a class trip to the Cornell Mission, the Code Busters learn about Hippolyte de Bouchard, California’s only known pirate. Now the Code Busters are on the trail of a new prize: pirate gold! But with a fortune at stake, the codes are bound to be hard. Will the Code Busters be able to figure them out, or will this mystery prove to be too difficult to solve?