Sail through the canal Nerrick opened and head west across the Aldean Sea. Dock at the port on the far continent - Melmond is right next to it. The town looks damaged, and for good reason. Something is rotting the earth itself.

Melmond Town
The buildings here are crumbling. The townsfolk blame a vampire in the nearby cavern. They're right, but the vampire is just the start - a Fiend of the Earth is draining the life from the land.

Melmond sells Level 5 spells for 4,000 Gil each. Curaga and Life are the priorities for your White Mage - Curaga heals more than Cura, and Life revives fallen party members. Firaga is your Black Mage's new damage spell. The armor shop has a Silver Armlet (4,000 Gil) if your mages need better protection.
Cavern of Earth
Head west from Melmond, then south through a narrow strip of land between mountains. The Cavern of Earth entrance is at the base of the northern mountain range. This dungeon requires two visits: one to fight the Vampire, and another to defeat Lich after you get the Earth Rod.

Before entering, stock up on Gold Needles. Cockatrices on the lower floors can petrify your party members, and Gold Needles are the only cure outside of the Stona spell. Check the bestiary for enemy weaknesses - many are vulnerable to Fire.
Upper Floors
The first floor has treasure rooms along the north and south paths. Grab the Gil and items, then take the stairs on the east side down to B2. The northeast room has a Coral Sword and a Tent. The southwest room has more Gil. Take the southern stairs to B3.
B3 is where things get dangerous. Earth Elementals and Trolls appear here - both weak to Fire, so use Fira. Work through the rooms grabbing treasure. The Vampire waits in the room at the end of the winding path, with a Star Ruby in a chest nearby. Heal your party before entering.
Vampire

After the Vampire falls, grab the Star Ruby from the chest if you haven't already. There's a stone plate on the floor past his room - you can't do anything with it yet. Leave the cavern and rest at Melmond.
Getting the Earth Rod
The Star Ruby opens the path forward. Head west from the Cavern of Earth to find a small cave called the Giant's Cave. Inside, a titan blocks the passage. Give him the Star Ruby and he eats it, then lets you pass.

Grab the treasure from the room behind him - a Great Axe and Mythril Helm are in there. Exit through the back of the cave.
Follow the path south to another small cave: the Sage's Cave. Inside, the sage Sarda recognizes your quest and hands over the Earth Rod.

Return to the Cavern
Return to the Cavern of Earth and fight back down to B3. At the stone plate past the Vampire's room, use the Earth Rod. Stairs appear leading to B4.
Lower Floors
Two more floors of tough enemies. Hill Gigas, Sphinxes, and Ogre Mages patrol these halls. The treasure rooms have more Gil and a Mythril Shield. Conserve MP where you can - you need Curaga and Firaga for Lich.
B5 leads to the Earth Crystal chamber. Heal up and save your game before entering.
Lich

Defeat Lich and the Earth Crystal is restored. The rot recedes from Melmond. Step into the portal behind the altar to exit instantly. One Fiend down, three to go - rest up, then sail north to Crescent Lake.
Treasure Chests
This chapter covers two dungeons with plenty of loot:
- Cavern of Earth - 20+ chests across 5 floors including Coral Sword and Mythril Shield
- Giant's Cave - 4 chests including Great Axe and Mythril Helm