Vida and Chip try to unlock more items for their Ranger arsenal by performing "heroic deeds for hire", but learn that true heroism comes only in the face of danger. The Hydra Worm that created the underworld pit Morticon and company are trapped in, poses a growing menace to the surface world. To make things worse, the Mucor monster is sent, with an appetite for our heroes! Also, a mysterious figure saves Clare. Is he friend or foe, troll or goblin? Or neither and both? Nick finds out!