Rangers Apprentice: The ruins of Gorlan

This book I would like to recommend is the first book of a series of books. It is an adventure book about a young boy father is a knight and he wants to become a knight like him. But he is to small and he is apprenticed to a mysterious group called rangers. He learns how to shoot a bow and all the skills of a ranger. His mentor Halt is a grim faced man who rarely smiles. Will and Halt go on a dangerous mission to kill the most dangerous creatures. Kalkara.

Whats your favourite book from this series?