Geronimo's sister Thea Stilton narrates this new adventure full of 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. As a result, celebrities, VIRs (Very Important Rodents) and other glamorous mice will join the mouselings on the journey. 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.