This is the second book of John Flanagan, in the serie of the Ranger Apprentice. This book follows book #1.
On a special mission for the rangers, Will and his friend Horace, an apprentice warrior, travel to the neighbouring country of Celtica and discover an unsettling truth. Villages, mines and border posts are deserted. The Celts have disappeared. But Lord Morgarath is behind it. Before long, they discover that the king’s army is in danger of being destroyed in a treacherous ambush. Only Will, Horace, and a mysterious girl named Evanlyn, stand between them.
It is still a thrilling story, which I recommend to read for anyone who enjoys The Lord of The Rings or King Arthur.