The Ranger's Apprentice - Book Fifteen - The Lost Prince

Will Deal and his apprentice Maddie receive an urgent invitation to Araluen Castle. There they learn some surprising news: the Gallic prince disappeared and the Gallic king asked for help. All reports indicate that the young prince has been imprisoned by the dangerous and powerful Baron Joubert de Lassigny. King Duncan knows that sending an army to Gallica to rescue the prince could spark a war, but there is another possibility: to use the Frontier Corps.