Two soldiers transporting water at night are attacked by demons led by Beelzebub, who deliver some bottles to a remote town where their wells have dried up and they return with the rest to Demon Village.
Beelzebub easily defeats the group of bandits, but their vehicle is damaged so he, Rao and Thief have to walk through the desert. When they head near a trading hub, Thief goes on ahead to acquire supplies and a vehicle.
In an attempt to turn the citizens against Rao, Beelzebub and Thief, the King broadcasts a message that a group in a tank are stealing water and he offers a reward for their capture.
General Are's remaining two tanks chase tank 104 between rock formations. During the chase, Rao realizes that Beelzebub can communicate with him telepathically, so they disable one tank and bring Are's tank to a standstill.
Beelzebub leads Rao and Thief to the Legendary Spring, which they realize the King has kept a secret. Beelzebub detects someone nearby and comes across a group of frightened Picchi and their offspring who survived the "great explosion".
The Insect Men overwhelm and savagely attack Beelzebub. However, his demon body enables him to recover and he defeats them all. In desperation, Zeu detonates a bomb within an Insect Man's body, that destroys everything.
Rao invites Beelzebub and Thief to accompany him to take supplies to the Picchi. When they stop in a small town, they encounters an angel searching for an ancient magical urn. The angel declares himself a hero and attacks Beelzebub.
Ann takes the trio to meet members of the Resistance who report that King Jam is to executed the next day. She later reveals that she is the king's daughter. They split into two teams, with Ann and Beelzebub going to save the king.
As Rao and Thief try to leave with the Aquanium, they are confronted by the huge General Bred but they manage to escape when Bred punches a huge hole in the wall. Outside, Muniel strikes down Beelzebub with a massive lightning bolt.
With all five Aquanium crystals in their possession, Muniel and Bred activate the gigantic anti-gravity Flying Fortress Garam built many years ago by the Picchi and prepare to launch an attack on Sand Land.
Rao's group recover from being catapulted into Garam and head off in their tank to find the control room. They are intercepted by Bred controlling a huge metal exoskeleton so Rao sends Beelzebub off while he and Thief tackle Bred.
With its energy supply diminishing, Garam begins to fall and Ann convinces the crew to evacuate in its escape pods. When she tries to stop Garam from crashing and exploding, Bred comes to her aid .
