Riven

Augum, Bridget, and Leera want only to study new spells and make their legendary mentor proud. But when she unexpectedly departs on a crucial quest, they run afoul of a devious old witch and are forced to make a hasty getaway—straight into the hands of a notorious maniac known as the Blade of Sorrows. Prisoners of the Blade and his sadistic apprentice, the trio must face their greatest challenge yet: escape using nothing but an ancient spell with some nasty side effects. But more than their lives are at stake, for an entire kingdom’s hopes rest with their mentor—and she’s heading for a deadly trap.