"An adventure down under! Moldy mozzarella! A flock of sheep at Nicky's family's Australian ranch was losing all its wool, and no one knew why. Nicky and her friends the Thea Sisters headed to Australia and set off on a tour of the whole country in serch of clues. What happened next turned out to be a truly memorable outback adventure!" -- P. [4] of cover.

When the Thea Sisters visit Egypt to help look for the legendary ancient Treasure of the Sun, they discover that thieves are also after the hidden treasure, and it's up to the sisters to stop them.

Attending an adventure camp in Madagascar, the Thea Sisters enjoy learning about the region's exotic plant and animal species before discovering that someone has been stealing endangered animals from the jungle.--

"Join Thea Stilton and the Thea Sisters on an adventure packed with mystery and friendship! The Thea Sisters visit Mexico!"--