The Black Plague has descended upon the world, transforming its inhabitants into horrible creatures. The unicorns, who have been mysteriously spared this affliction, come under suspicion from all sides. Pryzm, a brave unicorn, and Karrock, a wise troll, are reluctantly obliged to join forces as they set off in search of the source of the evil that has befallen the mountain of the trolls, the forest of the elves, the mountains of the gnomes, and the marshes of the nymphs. This special duo sets off on a crusade in which they use their magic powers to bring back to life the host of creatures they encounter in the course of their perilous journey. The player can control Pryzm and Karrock as a single entity, but each will have its own powers.