Hello, Lauren! All the clues were indeed found by the end of Book 10. The new series begins a whole new adventure that will involve the 39 Clues and so much more. I can't wait for readers to get started. Trust me, it's awesome!

Well, that's great, Jack. I'm happy to hear it. Congrats to you -- and a big welcome to any of your friends who visit the site!

Hi, Lauren!
Well, it has to do with the way the word "cousin" is used. We think of first cousins and second cousins, but when the family tree goes further and further back, interesting things happen.
Let's look at it this way: you have two parents, so you (and any of your siblings) are related to each parent by one-half. You have half of each parent's genes. Now let's go back a generation. You have four grandparents, so you (and any of your siblings) are related to each of them by one-fourth. If you have first cousins, they too are related by one-fourth, because they share the same grandparents.
So think of your relationship to your parents as being the fraction with 1 on the top and 2 on the bottom, or 1/2. As you go back a generation, you change that bottom number by a factor of 2. So your relationship to your grandparents (and your first cousins) is 1/4. Your relationship to your great-grandparents is 1/8 -- and this is the same as your second cousins. They share your great-grandparents. Your grandparents are their great-aunt and great-uncle, and their parents are your parents' first cousins.
Go back another generation, and the relationships are 1/16. The cousins at this level are called third cousins. Pretty soon, we start getting to a blood relationship that's statistically insignificant.
Interestingly, one of our U.S. presidents, Franklin Roosevelt, married his fifth cousin once-removed, which means that Franklin was the fifth cousin of Eleanor's dad -- so the couple were pretty distantly related, by about 1/48, which would be .02.
So, going back to the Cahills, all of the branches date back to the children of Gideon and Olivia Cahill, who were born in the late 1400s. That's approximately 21 generations ago. This means that the relationships among all the Cahill branch descendants are 1 divided by 2 to the 21st power. That's 1/2,097,152, or a blood relationship of .0000004.
For various complicated reasons of geneological statistics, that number isn't exactly correct, but here's the interesting point: going back that far, chances are that we are all related at least by that amount to any random stranger. Yup, statistically speaking, Amy and Ian (or Arthur and Isabel) are as genetically related to each other as, say, I am to my mail carrier or to a random guy in France who makes umbrellas.
The difference is, the Cahills have kept track. They've kept a family tree all these years. (If I had access to my mail carrier's family tree, I'd find our common ancestors too -- and maybe get a free umbrella!)
Thus, Amy and Ian can trace their ancestry back 21 generations, but the word "cousin" is what we call "a word of art." It is a way of saying "we're related" but it ignores the fact that the blood relationship is virtually zero.
Got that? Bet you weren't expecting a math lesson, were you? 🙂

Excellent! I was just going to write you, as that's exactly the word I received from Editorial just moments ago! Glad to help in removing any impediments to reading.

Wow, what a dedicated parent! Well, that effort surely deserves a solution. Okay, I did a little sleuthing and found that you can order the set directly from Scholastic USA at this link. Hope this works, and all best to Ben on his birthday!

Hello, Ethan! Thanks so much for this thoughtful and thorough message, and for all the kind words. I’m happy you liked VIPER’S NEST and am impressed with your astuteness. Very good suggestion about Nellie! Here are answers to your questions:
1. We 39 CLUES authors don’t work together or talk about plots. Which means we can have more fun at parties, eating and telling jokes instead of working! Seriously, if we were to discuss the books, the conversations would leave out the other authors. Because of the tight publishing schedule, the books are written simultaneously (one author may be doing corrections on an about-to-be-published book while another is working on a second draft, while another is putting together an outline, while another is researching an idea, etc.). It’s crucial that each author knows every plot change, new character, etc. So rather than have individual conversations, we talk instead to our editor, who then passes the info on to everyone else.
2. I’m very bad with snail mail these days; in fact, I have a backlog of more than a year. On the other hand, this guestbook makes it much easier for me, and I do answer every entry.
3. I always wanted to be two things: an actor and a writer. And those are the only two things I've done to make a living.
I hope that answers everything, Ethan. Best of luck with all your own plans!

Hello, Owen! Thanks for writing. I would be delighted to Skype with your school, and November 4 would work fine! Here's how we usually work it:
Click here to send a private message, letting me know (1) what time you'd like to Skype, (2) what you'd like to talk about, and (3) how long an amount of time you'd like. The message will automatically come to me and also to Ms. Nooney at Scholastic, who can help make the arrangements. OK?
(If the link above doesn't show properly, here's the email address to use: authorvisits@peterlerangis.com)
I look forward to talking to you all!

Hi, Antonia! So glad you enjoyed reading LAST STOP. It remains one of my favorite books I've ever written. In some ways, I like REWIND even better. Hope you agree, and thanks for writing!

Hi, Carrie. So delighted you’ve enjoyed SPY X, and many thanks for the kind words. I get more mail about that series than just about anything else I’ve written. I was planning to write Books 5 & 6, but publishing is a very unpredictable business, and the series was canceled very suddenly for reasons beyond my and my editor’s control (more to do with the economy at that time, I believe). I wish I could have forged on, but unless a miracle happens, the series will remain at four books. Sorry I couldn’t provide better news, but I’m very glad your family had the chance to go along on the wild ride with Andrew and Evie!