Geronimo and friends have to get to the bottom of a crown jewel of a case!Checkmate, cheese-lovers, er, we mean chess-lovers. For once, all is quiet in New Mouse City, so Geronimo Stilton, Editor-in-Chief of The Rodents Gazette can report on an incredible chess match-up. On one side, Gary Goudov, world-renowned chess champion, and on the other side, a super chess-playing computer! But after Geronimo leaves, the infamouse Gem Gang commits a string of robberies that only the Stiltons can untangle. Can Geronimo, Benjamin, and Thea protect the good mice of New Mouse City from the greed of the Gem Gang? Find out in this cheddar-ific volume of GERONIMO REPORTER.