Why did you agree to write the last book in the 39 Clues series?
I thought it was an interesting and innovative project. I’d never written a book like this before, based on someone else’s ideas, and at the time I was telling a lot of other people in my family, “Oh, yes, take a chance! Do something new!” So I thought I should take my own advice.
Another factor was that, because of the secrecy surrounding the series, there were certain things I couldn’t know until I actually agreed to write the book. So that was scary, but also enticing. I wanted to know what was going to happen!
What was the hardest thing about writing this book?
The fact that, because of the timing, I had to start writing it before Books 7, 8 or 9 were in final form.
Who are your favorite characters in the series?
Oh, Amy and Dan, definitely. But I was surprised that, once I started writing, I also really enjoyed writing scenes from the perspective of Jonah Wizard, Hamilton Holt, and Eisenhower Holt.
What branch of the Cahill family do you belong to?
Ekaterina. The funny thing is, I have two nephews who have been really, really into the 39 Clues series. They both took the online test to see what branch they were in—and both of them were also Ekats. So it must be true! (Though I will say, fortunately my family is much, much, much more pleasant than the Cahills.)