Thea Stilton and the lost letters / text by Thea Stilton ; illustrations by Barbara Pellizzari and Chiara Balleello (pencils), Valeria Cairoli (base color), and Daniele Verzini (color) ; translated by Emily Clement.
It is up to the Thea sisters to investigate when their friend is falsely accused of theft and barred from competing in a figure skating championship in Russia.