Interest LevelReading LevelReading A-ZATOSWord Count
Grades 4 - 8Grades 2 - 5S4.713529
Geronimo's adventurous sister Thea narrates this fabulous adventure that's packed with action, mystery, and friendship!

In this amazing adventure, Thea's friends the Thea Sisters head to Peru, where a good friend of Paulina's is in danger. There, the five mice climb the Andes mountains in search of a mysterious treasure that's hidden in the Secret City of the Incas. Readers will love following the clues to help the Thea Sisters solve the mystery!
Mass Market Paperback, 176 pages
Published on June 1, 2010 by Scholastic Paperbacks
ISBN-10: 0545150612
ISBN-13: 9780545150613
9 Book Reviews
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  • WreckersWednesday, May 16, 2018 at 9:19 pm
    I love this book
    • Catlover12345loWednesday, May 16, 2018 at 9:18 pm
      Lol this author rocks and I love condors I would love to visit Peru someday
      • matthew1234
        matthew1234Monday, February 1, 2016 at 9:28 am55 stars
        This book was really good because it must be fun to visit Peru. I like the part when they flew a condor. A condor is a kind of a predator bird. The sisters names are Thea, Nicky, Colette, Violet, Paulina, and Pamela. This is my book summary.
        • diego1234
          diego1234Monday, February 1, 2016 at 9:19 am
          This book is very interesting and adventure type of book. The funny thing is that mice are like humans. Whoever made this book should keep up the good work. I love these types of books and I love the way how the author showed their expressions and feelings. I'll like to read more books like this one.
          • president
            presidentFriday, May 2, 2014 at 9:53 pm55 stars
            I love this book a lot. It is one of my favorite books.It is a mouse called Paulina and her friends, the Thea sisters. Her cousin, Gonzalo, got lost when he was searching for the secret city. It is not really a city, but it is a place where people from long ago had kept treasure in it. Gonzalo's father is dead worried about him. So, Paulina and the Thea sisters search for Gonzalo in Peru, where the Secret city is located. Will the Thea sisters find Gonzalo and find the treasure.
            • president101
              president101Wednesday, April 30, 2014 at 7:11 pm55 stars
              Thea Stilton and The Secret City is one of my favorite books that I have read. It is about mice. But, they are cartoon mice. This story is about a mouse called Paulina in search of her cousin who is lost in Peru. His name is Gonzalo. He got lost while he was searching for the Secret City. The Secret City in Peru is where mice from long ago kept their treasure in this very place so, none would be able to find it. But, there no buildings and street lamps because it is not a real city. Will Paulina find her cousin, Gonzalo, and find the secret city?
              • asa12
                Mrs. MerliniThursday, April 4, 2013 at 3:59 pm
                this is going to rock my class.
                • cima11
                  cima11Sunday, March 24, 2013 at 5:04 pm
                  I can't wait to read this one!
                  • cima11
                    cima11Sunday, March 24, 2013 at 5:03 pm
                    I have read many of the Thea Stilton Editions and I have loved them all. They give you clues to see if you can solve it first. It is also filled with tales of friendship and mystery! Anyone who loves a good mystery MUST READ THIS BOOK!