Secret of Mana/The Underground Palace

Water Palace
You are called back to the water palace. When you go through the Mysterious Forest, you can now use the whip to swing across a gap and take a faster shortcut. If you wish to gain experience, you are free to take the longer route as well.

When you reach Luka, she will heal you, and mention that the seal on the Water Temple is weakening. You will need to enter a cave to the east of the temple and meet Undine.

Undine's Cave
Undine's cave is initially protected by Iffish, appearing in groups of three. When you proceed north, you will encoutner the Tonpole.

The Tonpole is a small enemy, which will simply hop around and damage characters it enters contact with. When it takes enough damage, it will transform into the Biting Lizard.

Neither of these two bosses are a threat themselves, and are easily defeated using continuous attacks. While the Biting Lizard will cast Cure Water, it only does so twice.

When the Biting Lizard is defeated, a cave is opened to the north. After speaking with Undine, you will have obtained a Glove orb, the Polt Dart weapon, and the ability to cast water magic.

Undergound palace
The path to the underground palace is blocked, but can be opened with water magic. Return to the Dwarf village near Gaia's Navel, and enter the cavern opened by Tropicallo. Cast freeze on the crystal to open the palace. This cools the lava and opens the first door.

The underground palace has the five major rooms:


 * 1) In the first room, you will encounter goblins guarding a door.  Behind this door is the stairs, blocked by a large torch.  Head to the left and right to press the floor switches to remove the torch.
 * 2) The second room snakes to the left, and requires using the whip to swing across.
 * 3) A few goblins will guard a small room.
 * 4) This room is shaped like a "U", with Goblins and Chess Knights. The only exit is on the left.
 * 5) The final corridor before the stage contains a few goblins, before you climb up the stairs.

Once you climb the stairs, a cutscene will appear with Gnome blocking access. However, a monster approaches, causing the Gnome to flee.

Boss: Fire Gigas
Defeating the Fire Gigas will give you another Axe orb. Proceed north into the mana seed room, where you can learn earth magic and use the sword with the mana seed. Once this is complete, all monsters in the underground palace will disappear. Popoie's memory will return, and he will mention that he lived in the Upper Land forest and that you'll need to head there.

You can't do that yet. When you return to Luka, you will learn that Jema hasn't yet returned from Pandora. You will need to head there to rescue him.