Kazuma runs into some adventurers he knows while out for a walk and decides to go with them to a shop run by succubi said to show its customers enticing dreams.

The rampaging ancient weapon: the mobile fortress, Destroyer, is headed straight for Kazuma and party's city!

Kazuma and the gang fail to defeat the hydra in the lake near Axel. The gang hopes to rely on knights from the capital, but they've been delayed due to a bandit disturbance for which a bounty has been issued. Darkness, however, is obsessed with the hydra.

Kazuma has crashed Darkness's wedding to Aldarp and pays him the two billion eris he says he's owed. Aqua and Kazuma try to make off with Darkness but Aldarp won't relinquish her so easily and orders his guards to stop their escape.