Geronimo's adventurous sister Thea narrates this fabulous adventure that's packed with action, mystery, and friendship!Thea's friends the Thea Sisters take off for Australia to solve a mystery. A flock of sheep at Nicky's family's ranch is losing all its wool, and the ranch depends on the wool to stay afloat! Maybe the sheep's cure lies in an Aboriginal medicine containing a strange root. The five mouselings set off on a tour of the whole country to find out. It's a truly memorable outback adventure!

Thea's friends the Thea Sisters take off for Australia to investigate why the sheep at Nicky's family's ranch are losing all their wool.

Geronimo's adventurous sister Thea narrates this tale packed with action, mystery, and friendship!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 stop the destruction before it's too late?

When the sheep on Nicky's family's ranch start losing their wool, the Thea Sisters head to Australia to investigate.

Join Thea Stilton and the Thea Sisters on this adventure packed with mystery and friendship! The Thea Sisters are in Kenya on a photo safari! The mouselets love exploring the magnificent landscape and learning about the animals on the reserve they're visiting. A lion cub has just been born -- but while they're there, he's kidnapped! It's up to the Thea Sisters to rescue him in an adventure across the savanna.

Geronimo's adventurous sister Thea narrates this fabulous adventure that's packed with action, mystery, and friendship!The Thea Sisters are boarding the famouse Orient Express for a journey from Paris to Istanbul! The train is on a special trip to return a precious wedding dress stolen years ago from an Istanbul museum. But there's a rumor that the mysterious Acrobat Thief will steal the dress from the moving train! The Thea Sisters are determined to foil this super-sneaky mouse's plans.

Join Thea Stilton and the Thea Sisters on an adventure packed with mystery and friendship! One of the Thea Sisters' favorite authors, a famouse mystery writer, has disappeared! To find him, the five mice travel to his native Iceland. Together they traverse the stunning landscape and reconstruct the plot of the author's latest novel. But it's more dangerous than they expected! Can the mouselets locate their beloved author, or will their search just end up as an icy mess?

Join Thea Stilton and the Thea Sisters on an adventure packed with mystery and friendship! The Thea Sisters spend the holidays in Rome!

The Thea Sisters are on a magical adventure! The Thea Sisters' next adventure to the Kingdom of the Fairies!

Geronimo's adventurous sister Thea narrates this fabulous adventure that's packed with action, mystery, and friendship!In this exciting adventure, the Thea Sisters are off to Paris to visit Colette's fashion-designer friend Julie. But when Julie's designs are suddenly stolen, the girls must search the city of Paris to catch the thief and save the fashion show. Readers will love following the clues to help the Thea Sisters solve the mystery!