The Second Battle of the Underworld is a battle between the dwarves and the Red Wings of Baron. The Red Wings attack the dwarves to claim the four Dark Crystals, and although the dwarves fair well against the Baron airships, they are defenseless against the Maenads accompanying them. The Maenads apply the same tactic that was used in their previous assault on Baron, with summoning monsters and penetrating the opposition's defenses through wave attacks.
Having captured the four Light Crystals of the Overworld, the Maenads turn on the dwarves who possess the four Dark Crystals. Arriving on a Red Wings airship, a Maenad single-handedly takes on the defenses of Dwarven Castle, summoning monsters to overrun the castle guards. After a brief battle the castle's Crystal is stolen, alongside with two other Crystals in unspecified locations in the Underworld at the same time.
Dwarven Castle takes little damage from the bombing, King Giott describing it as "feeble." The dwarves suffer only moderate casualties, and the mood in the castle is light even immediately after the battle. That doesn't change the outcome of the battle, and dwarven guards comment on how easily the Maenad and her monsters pushed the best dwarven guards aside. Some guards mention they fought the Red Wings seventeen years ago, describing them as "suckers." King Giott, knowing King Cecil Harvey of Baron is a good man, rightfully suspects something is amiss.