While salvaging a Viking ship submerged off the coast of Mouse Island with their Mouseford Academy classmates, the Thea Sisters learn that someone wants to steal the vessel's historic treasure.

The Thea Sisters are five fun, lively students at Mouseford Academy on Whale Island, who want to be real, live journalists, just like their hero, Thea Stilton. Between classes, friendships, crushes, and some bizarre mysteries to solve, they find life to be a never-ending adventure! Mouseford Academy is planning a spring field trip to the waterfall in the forest, but angry bears are chasing people! Something strange is going on--could Vissia de Vissen...

"Journalist Zoe Meadows is on a break from hard-hitting investigative reporting to spend more time with her family, which is how she finds herself doing celebrity Q&As at an outdoor music festival. She and her friends, who run a food truck, head north, along with 150,000 festival-goers for a weekend of music and camping. When some of the revelers fall ill, many point to food poisoning. But after the festival ends and attendees scatter across England,...