The 39 Clues, Book 6: In Too Deep

The 39 Clues, Book 6: In Too Deep by Jude Watson

In the sixth 39 clues books, the heroes explore Australia and Indonesia. There are surf "attacks", gliding in escapes and many bits of action. The kids uncover more about their parents deaths, but have even more challenges trusting people.

Beyond the Grave (The 39 Clues, Book 4)

Beyond the Grave (The 39 Clues, Book 4) by Jude Watson

In book 4, the heroes journey to Egypt in attempts to find clues. They make and break allegiances as they seek to find the clues.