The Siege of Macindaw by John Flanagan
Will and the warrior, Horace, hold the fate of the kingdom in their hands. Sir Keren has captured Castle Macindaw after poisoning its rightful leaders. He plans on letting the Scotti in to Araluen, where they plan to take over the who country. Will and Horace quickly round up a small army of Skandians and outcasts who live in the forest.With so much at stake, they cannot afford to make any mistakes. But the kingodm is not the only thing is terrible danger. Will's friend, Alyss, is being held captive by Keren and who knows what he plans to do with his prisoner.
**Book 6 in Ranger's Apprentice**
Previous book: The Sorcerer of the North
Next book: Erak's Ransom