Geronimo goes to Athens to report on the Olympics, and after observing some of the games he and detective Hercule Poirat become suspicious about Cyrus von Snootrat who seems to be winning every Olympic event and they decide to investigate him.

"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...

When the owner of the Daily Rat newspaper thinks Thea Stilton, who has vanished without a trace, is responsible for a recent string of robberies in New Mouse City, Geronimo must employ his "famouse" investigative skills to find Thea - and the truth.

"Geronimo Stilton's dealt with mummies, ninjas, and pirates, but this may be the first time he's come face to face with ... ghosts! Can the scaredy-mouse overcome his fears and get to the bottom of the mystery for a big scoop for his newspaper, The Rodent's Gazette? For help, who's he gonna call? His ghost-bustin' relatives, of course! Geronimo and his family need to travel to a haunted museum in Africa for this globe-trekking, teeth-chattering spooky...