Tommy is a child with a passion for reading. He spends most of his time in the library reading, and it is here that he meets Nero Mouse, who comes out of a trapdoor under the big carpet. Nero is a mouse, but not just any mouse... is the founder of the Agency Investigalibri!

Manuel is a thirteen-year-old boy who lives with his parents and two sisters in the Algarve in southern Portugal. It is a poor family. His father and mother work in the fields. He studies, reads a lot and dreams of a better future. But...

Luisa and a gold fish, what do they have in common? Is Mitch’s friendships with Brando really strong?
Should Giacomo stop daydreaming? Never expected, often surprising and “upstream” the stories in Against the tide are smart and poetic.

The series of books XS (eXtraSmall) but better known by young readers as Investigalibri, is a series of novels for readers between 7 and 10 years of age that has as its protagonist a book detective Black Mouse, a fat and lazy mouse and his helper a young avid reader, a young boy but who is a bookworm, called Tommy Trevis