The Phantom of the Subway / The Temple of the Ruby of Fire (Geronimo Stilton #13 & #14)

I'm Geronimo Stilton. I run a newspaper, but my true passion is writing adventure stories. In my next two adventures I try to keep a legendary gem hidden in the heart of the Amazon jungle from falling into the wrong paws and search the subway tunnels of New Mouse City for the latest ghost haunting, only to find the fight of my life-the ghost turned out to be a cat!