Beast Quest: Narga the Sea Monster : Series 3 Book 3

Battle fearsome beasts and fight evil with Tom and Elenna in the bestselling adventure series for boys and girls aged 7 and up. 

The good Beasts of Avantia are in danger. They have been captured by six terrible new Beasts and taken to Gorgonia, the kingdom of evil wizard Malvel. To free the Beasts, Tom journeys into the sinister Dark Realm, where he must face some of the deadliest beasts he's ever fought..