The 39 Clues: Cahills v. Vespers, Books 4-5

Book 4 by Roland Smith
Book 5 by Linda Sue Park

Amy and Dan continue to do the bidding of Vesper One, but only because he holds seven members of their family hostage.  At least they have added Atticus and Jake to their team.  Unfortunately, there is still trouble at every turn, and each time they think they have accomplished something, Amy and Dan are met with a new challenge.

Mrs. Senechal says:
I've been holding off reading these books because every time I finish one, I can't wait to read the one that follows.  So, with a snow day following a weekend, I thoroughly enjoyed reading these two!  As you can expect from this series, the suspense and adventure never slow down.  I love the detail that goes into each historical item or new city they visit.  And now, Book 6 - here I come!