The Secret Invention (Thea Stilton Mouseford Academy #5): A Geronimo Stilton Adventure

The students of Mouseford Academy are participating in an enormouse science fair! Mice from schools around the world are all hoping to take the top prize. The Thea Sisters would love to win, but so would Ruby Flashyfur - and shes willing to do whatever it takes! Can these mice play nice, or will the science fair be a total flop?