The underwater planet /
Geronimo Stilton ; translated by Anna Pizzelli.
- New York : Scholastic Paperbacks , 2016.
- 113 pg. : col.ills ; 20 cm.
The spacemice follow it and end up on Aquarix, a planet that's entirely underwater. During their exploration, they face fur-eating seaweed, ferocious piranha aliens, and pirate spacecats.