Geronimo Stilton, editor-in-chief of the rodent newspaper, is known for regularly bringing sensational news to residents by publishing it in his publication. But recently, Sally The Rat, owner of the competitive publication rat daily, intercepts Geronimo's sensations and passes them off as her own! Geronimo is sure that there is a spy in his newspaper, and with the help of ladder and Benjamin, he sets up a trap in which he hopes to catch the enemy scavenger. But the main thing is not even this, but this: will Geronimo be able to keep a secret from everyone, and above all from Sally, who exactly is the star that the mayor of Myshania invited to be the host at the celebration of the hundredth anniversary of the founding of the city?