Notes

353 pages :illustrations.
Summary: Mr. Quisling is definitely up to something mysterious, and Emily and James are on high alert. First, there's the coded note he drops at a book event. Then they uncover a trail of encrypted messages in Mark Twain-penned books hidden through Book Scavenger. What's most suspicious is that each hidden book triggers a fire. As the sleuthing friends dig deeper, they discover Mr. Quisling has been hunting a legendary historical puzzle: the Unbreakable Code.