King Duncan and Princess Cassandra are trapped in the south tower of Castle Araluen and under near-constant attack from the Red Fox Clan. Sir Horace and Ranger Commandant Gilan are holed up in an old hill fort, surrounded by the enemy. With the help of Hal, Thorn, and the rest of the Heron brotherband, Ranger's apprentice Maddie will have to break her father and his men out of the hill fort. But will they reach Castle Araluen in time? -- adapted from jacket.