Erak's Ransom

Erak's Ransom is the seventh book in the Ranger's Apprentice series by Australian author John Flanagan. The story revolves around the Skandian Oberjarl, Erak Starfollower, who, in an attempt to rescue his crew from a desert tribe, gives himself up for ransom. His loyal Rangers, together with Princess Cassandra, embark on a dangerous journey across the desert to secure his release.