"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 a member of their group goes missing, the Thea sisters head to Niagara Falls to find him.

The Thea Sisters help their friend Beatrice prepare for the Summer Olympics!

"In this fabumouse adventure, the Thea Sisters head to Alaska, where they're attending a conference held by an important ecological association. Their host and his family are native Alaskans, who show the mouselings their favorite games and activities. But soon there's trouble - the Thea Sisters discover that someone is upsetting the ecosystem by blowing up the ice with explosives! Can the Thea Sisters figure out what's going on and save the day?"--Publisher....

While five little mice at Mouseford Academy are looking for their missing biology professor, they dive to a haunted shipwreck off Whale Island to find a rare diamond that was lost when the ship sank.

Taking a road trip to San Jose along Route 66 while stopping in Chicago, St. Louis, and other iconic cities, the Thea Sisters are dismayed to learn that an unknown saboteur has wiped a special video game project off of a programmer friend's computer.

Join Thea Stilton, a special correspondent for The Rodent's Gazette, as she and the Thea Sisters spend the holidays in Rome.

For the first time ever, Mouseford Academy is offering a course in outdoor survival skills, and it's being taught by the athletic adventurous Bruce Hyena! All five Thea Sisters sign up, along with the Ruby Crew. But when a terrible storm hits during the two-day outdoor challenge, there are mouselets in danger! Who will come to the rescue? -- Back cover.

The Seven Roses, magical flowers which bloom forever and which are linked to the health of the Land of Flowers, are dying, and the Thea sisters together with Will Mystery must travel to that land to discover the reason--a journey where every flower seems determined to hinder their passage.

"The Thea Sisters travel to New York to cheer for Nicky as she runs the Big Apple Marathon. While there, they visit Pamela's family and have a delicious dinner at the family's pizzeria. But when someone threatens to burn the restaurant down, can the Thea Sisters catch the troublemaker and solve the mystery?"--P. [4] of cover.