The 39 Clues

The Sword Thief by Peter Lerangis
There's only one rule in the race to find 39 Clues hidden around the world: Trust No One. But when the hunt leads Amy and Dan to Japan, their only chance to find the third Clue seems to lie with their unreliable uncle, Alistair Oh. Will they be foolish enough to make an alliance? With a Clue on the line, Amy and Dan might not have a choice. But in the Cahill family, trusting your relatives can get you killed. 
Hardcover pages 156      Reading Level 4

Beyond the Grave by Jude Watson
It's off to Egypt on the hunt for the fourth Clue that lead to a source of unimaginable power. But when they arrive, Amy and Dan get something completely unexpected - a message form their dead grandmother, Grace. Did Grace set out to help the two orphans...or are they heading for the most devastating betrayal of the them all?
Hardcover pages 190       Reading Level 4

The Black Circle by Patrick Carman
A strange telegram lures Amy and Dan deep into Russia and away from the only trustworthy adult they know. Signed with the initials NRR, the telegram launches a race to uncover a treasure stolen by the Nazis and the truth behind the murder of the last Russian royal family. All too soon, the treasure hunt starts to smell like a Lucian trap. But the bait might just be irresistible...what will Amy and Dan risk to find out what really happened on the night their parents died?
Hardcover pages 168      Reading Level 4