The Lost Spell of Avooblis - The Adventurers' Academy, #7

Avooblis's power is sweeping across the land, and villages everywhere are in dire need of a hero. Dagdron, Earl, Elloriana, and Lita have returned from the lava land, but they still must heal the heart stone if they have any hope of fulfilling their quest before the darkness takes over. As the adventurers search out the Lost Spell of Avooblis, Mazannanan will stop at nothing to prevent them from uncovering the secrets of his past and recovering the cursed gifts of the land.
With peril lurking along every pathway, the rogue, warrior, enchantress, and lady warrior must put their skills to the test and rely on their friendship if they have any hope of having a legendary adventuring career before Avooblis brings it to an untimely end.