Thea Stilton #4: Thea Stilton and the Secret City

Geronimo's sister Thea has her own bestselling series! 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!