Lina and Gourry bump into some pirates on the high seas, and demonstrate they still got what it takes to beat up the bad guys. The pirates have a fish woman who was taken hostage. Zelgadis travels with Amelia, who brings her Seyruun fleet to Lina. As the gang reunite, a guy named Wizer Flayon, an inspector from the kingdom of Ruvignald, proceeds to arrest Lina Inverse with the crime of being Lina Inverse. As the gang try to bail out of town, they encounter increasing military opposition and someone who can cast a Dragon Slave!

Lina's party reaches the outskirts of Ruvinagald but Wizer is there to arrest her, and has taken the time to build an elaborate building full of traps and tricks. That should be a cinch for Lina, but thanks to Wizer's alliance with Xellos, the traps are especially devised to exploit Lina's weaknesses, such as her desire to push buttons that are marked "do not push". And when Xellos himself becomes one of the obstacles, Lina's group is in serious trouble.