The Battle of Hackham Heath (Ranger's Apprentice: The Early Years Book 2) - John Flanagan - Bog

The peace in Araluen is under threat and newly crowned King Duncan must prepare for war. Morgarath is in hiding, recruiting an army of savage beasts known as Wargals for his next attack. Halt prepares for a seemingly impossible task - to scale the Mountains of Rain and Night to spy on the enemy and uncover their plans.