An all-new hardcover adventure featuring Thea Stilton and the Thea Sisters! At the beach by Mouseford Academy, one of the Thea Sisters discovers a mysterious boy with blue skin washed up on the shore. He speaks an unfamiliar language, so the Thea Sisters call Thea Stilton to help figure out how to communicate with him. She sets the mouselings on an exciting journey across the world to hunt for clues about the boy's origins. Could he be prince of the underwater world of Atlantis? It's up to the Thea Sisters to get him home!

A magical world is in danger! The Thea Sisters are on their way... Thea Stilton and the Thea Sisters are on an expedition to the fantastical Land of Erin. While they are searching for a missing friend, they learn that the land itself is in peril! The mouselets are ready to help. On their journey, they encounter fairies, pixies, and other magical creatures—some helpful, but some out to trick them! Can the Thea Sisters save the Land of Erin before it's too late? It's an adventure full of mystery and friendship!

Join Thea Stilton and the Thea Sisters in their third magical special edition adventure! There's a mystery in the land of the lotus flowers! Thea Stilton and Thea Sisters are called to help to an enchanted land! It's a world linked to the legends of Japan, and it is in danger. The realm's special lotus flowers are disappearing, and no one knows why! The mouselets set off on a quest to solve this mystery. They must discover the secret of the lotus flowers—but can they trust the strange magical creatures that they meet on their way? It's a fabumouse adventure!

What is the secret of the clouds? The Thea Sisters have received an urgent message from their friend Will Mystery. The magical Land of Clouds is in danger. The mouselets must find out why the clouds are disappearing!Once they enter the kingdom through Mount Everest, the mice meet fairies, elves, and unicorns on their way to the majestic Cloud Castle. But who can the Thea Sisters count on to help solve the mystery? It's an incredible journey to restore harmony to this enchanted land!

Thea Stilton and the Thea Sisters are needed to help another magical land. The music of the sea has disappeared from the depths of the enchanted Land of the Ocean! If it doesn't return soon, the kingdom will perish. The mouselets and their friend Will Mystery travel to the underwater realm to search for the magical music. On their way, they swim through dangerous waters, reveal an ancient mystery, and encounter many hidden, fantastical creatures—some friendlier than others. It's an aquatic adventure!

In de fantastische wereld van Bloemenbloei is iets vreemds aan de poot: de duizenden bloemen en planten verwelken en de prachtige kleuren en overheerlijke geuren van het rijk lijken voorgoed te vervagen. Als onderzoekscentrum de Zeven Rozen de Thea Sisters oproept om het rijk te hulp te schieten, blijkt bovendien dat niet alleen Bloemenbloei maar alle fantasiewerelden in gevaar zijn! Werk aan de winkel dus voor de vijf studentes van het Topford College. Eenmaal op de plaats van bestemming komen ze erachter dat Bloemenbloei wordt geregeerd door de tweelingzussen prinses Lotus en prinses Althea. Maar Althea is sinds kort spoorloos en ze heeft iets kostbaars meegenomen ... iets dat onmisbaar is om Bloemenbloei weer op te doen fleuren. Lotus maakt zich ernstige zorgen. Waarom heeft Althea dat gedaan en wie is de mysterieuze ridder waarmee de prinses voor het laatst gezien is?

Join Thea Stilton and the Thea Sisters on an adventure packed with fantasy and friendship! The Thea Sisters are just about to head off on their separate family vacations when they receive a call from Will Mystery. Once again, there is trouble in one of the imaginary kingdoms! A crack has been discovered in one of the maps in the Hall of Roses. The girls head to the Crystal Kingdom to help uncover the mystery. There, they find that a dragon has been wreaking havoc all over the land. He has been turning all of their precious gems into stone and leaving a path of destruction whereever he goes. The sisters figure out why and help break the spell.

The Thea Sisters are on a magical adventure! The Thea Sisters were are needed in Starlight Kingdomthe Kingdom of Starlight. All of the stars in the sky of the kingdom's sky have been losing their shine and the sky is about to go dark!The mouselets head to Brightstar Castle to figure out how to get stardust back to the kingdom! Will they be able to return the light to the sky, or will all of the stars burn out?