This is book number 44 in the Geronimo Stilton series.
I, Geronimo Stilton, am no sportsmouse. But that didn't stop Grandfather William from dragging me to a golf tournament so I could be his caddie Once I arrived, who should I bump into but my friend Kornelius Von Kickpaw, a.k.a. Special Agent 00K. Someone was plotting to steal the Super Mouse Cup, and it was up to me and Kornelius to crack the case.