The series begins with a raid on a group of bandits at the hands of the 15-year-old sorceress Lina Inverse. On her way to Atlas City, she is surrounded by bandits. Just as Lina prepares to attack, a mercenary swordsman, Gourry Gabriev, appears and defeats the bandits. Lina and Gourry befriend each other. Soon after, Lina and Gourry are asked to exterminate the dragon threatening a small village. Having no reason to refuse, Lina takes on the job despite Gourry's dissuasion. Being intimidated by the dragon, Lina is outraged. Lina uses the Dragu Slave technique on the dragon, killing it and destroying most of the village. Lina and Gourry eventually run away from the villagers after the village's destruction.

Lina and Gourry go to a magic shop in town to sell the treasures that Lina snatched from the bandits. However an item from the booty, a knife, is cursed and it turns the shopkeeper violent and a hullabaloo starts. Lina and Gourry fight a hard battle but the chaos is brought to a sudden stop by a single bark of the shopkeeper's wife. While they are relieved, a mummy called Zolf, attacks our heroes with the evil trolls. He is looking for one of the items Lina possesses. Lina and Gourry are fighting their way out. However, on the same evening, Zolf shows up to their room again with a mysterious person.

The mysterious person says that his name is Zelgadis Greywords. He is a mixture of human, golem and demon; a creation of utter evil. He offers to buy Lina's booty, but Lina asks for an outrageous price which drives him away. Not giving up, Zelgadis comes back to take Lina's booty by force. Lina is hurt and thrown into a pinch. Luckily she is saved by the legendary great sage, Rezo the Red Priest. Rezo warns Lina that Zelgadis wants to resurrect the mazoku Shabranigdo, the demon king, then Rezo mysteriously disappears after performing some unknown spell...