Books from the Backlog - The Unbreakable Code

Today I'm linking up with Carole from Carole's Random Life of Books for Books from the Backlog.  I really enjoy the chance to feature a book that's been hiding in the piles of books for far too long!

Goodreads:  The Unbreakable Code by Jennifer Chambliss Bertman

Blurb:  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 an arson fire.
As the sleuthing friends dig deeper, they discover Mr. Quisling has been hunting a legendary historical puzzle: the Unbreakable Code. This new mystery is irresistible, but Emily and James can’t ignore the signs that Mr. Quisling might be the arsonist.

The clock is ticking as the arson fires multiply, and Emily and James race to crack the code of a lifetime.

Why It Needs to Come Off the Shelf:  I read the first book in this middle grade series years ago and really enjoyed it and meant to read this one as soon as it came out...