After contracting with Undine, Ifrit, and Gnome, you are ready to go to Moria.
You can reach Moria from Alvanista. Buy food and supplies there, and get at least two Rune Bottles. Get Remedy Bottles as well. Cless/Cress should be equipped with Gungnir or another non-elemental weapon.
Remember to get your Moria pass from the guy behind the counter downstairs at the Adventurer's Guild before you leave, if you didn't get it before.
From Alvanista, cross the bridge to the east, then go south, then go east where you can see the dock that leads to Freland, and go east and north from there to find the entrance to Moria.
After the guard checks your pass, go to the northwest part of this room to find a chest (Orange Gummy), then go farther left to pull a switch in the wall. Go all the way to the right to reach the next room, then go through the door and down the stairs.
Step on the switch to the right to open the door, and go through. Go up and you will see a sign. There is a chest hidden behind the sign. Open it to get Lavender. Then go left to the next room. Pull the statue down and onto the switch. Go down to the bottom of the room to find some chests. From right to left, they contain a Protect Ring, Steak, and 2000 gold. Then pull the lever. Go back to the last room, and keep going right to reach the next room. Go through the door and go down.
Go right from the stairs, then go all the way to the top. Walk over the ON symbol to float. Return to the stairs and go left, but don't step on the off symbol. Go through through the door above. Keep going north until you reach an OFF symbol. Float over it to land. Then go to the right, step on the switch, and go through the door. Follow the path to reach a room with a statue. Pull the statue so that it is not standing on the switch, then go down through the door. From there, go to the right and go down the stairs.
Go left until you see a torch that isn't lit. Check on it a couple of times, then pull on the torch to open the path. Go up the path and go through the open door. In this room, step on one of the switches and wait for the woman to step on the other, and then open the chest that appears. It contains a Rune Bottle. Exit the room.
Press the switch to open the other door. Go through. The sign in this next room says "up up down down left right left right". Go left to the next room, where there are four switches. Walk on the switches in the order that the sign said. If you make a mistake, just start over. If you did it correctly, you will hear a sound. This means that a door has opened in another room. Go to the right, take the first path leading down, step on the switch and pull the lever. If you go through the door that you just unlocked, you can go straight up to the first floor. This makes it easy to leave the cave and buy supplies or heal up if you need to.
Otherwise, go back to the room with the four switches. Pull the statue through the door and onto the switch, then go down to the next level.
First, go all the way to the right to reach the next area, then go all the way up. From there, go to the right to reach a door. Hit the switch and go through. Equip the Sorcerer's Ring on somebody and shoot the switch in the wall. Then leave the room, and walk left to the next area. Go down so you are close to the wall, then walk left. Go past the first downward path, then when you see a part of the wall that is lower than the rest, go down through it.
Go through the door to your right. Then walk to the right, over the spikes, into the next room. Go through the open door. Pull down the rightmost statue and pull the lever that was behind it. Go down and open the chest (Lemon Gummy), then go back and move the statue back onto the switch. Go to the left side of the room, then keep going down to find the stairs to the next floor.
Use the Sorcerer's Ring to light the unlit torch. Then step on the transporter. In the dark room, go to the right and go around the room to get the chest. You have to go the long way around or you will be transported just before you can reach the chest, which contains a Lemon Gummy. After you open the chest, walk forward to be transported. Then step on the transporter again and go the long way to get the chest. After the Lemon Gummy, you get a Yellow Cake, then a Mystic Broom, which you should equip on Arche now. After that, you reach a room with candle holders. Light all the candles with the Sorcerer's Ring, then go through the door that opens. Go up to find a path. Follow that path to the next room. Break down the wall, light the candles, and go south and through the door.
Unequip your Sorcerer's Ring and go up to the candle holder. Check on it to throw the switch. Go through the door and step on the switch, then go back to the last room and walk over the ON symbol to float. Go north to the room where you stepped on the switch, and follow the path. When the path splits, go down to find a chest (Yellow Cake). Then go north, then east, and follow the path to the next room. Go straight down to find chests. From left to right, they contain a Rune Bottle and an Apple Gummy. Go up the stairs, then go all the way to the left, then go down and right to find a door.
Go to the right, over the holes in the ground, then go up. Hit the switch and go through the door. Go left and pull the lever. Now you can go straight up to floor 1. You can leave Moria to buy supplies and heal up if you wish.
Go to the right and up. In the next area, go to the right and follow the path. Hit the switch, then go back the way you came. Equip your Jet Boots, then go underneath the dripping water and wait for it to drop on your head. Then run across the holes in the ground that are now flaming. If the water dripped on your head, you won't get hurt by the flames. Go north through the door, then go down the stairs.
Pull the switches on the wall and open the chest (Turquoise Ring). Walk onto the transporter on the right, then go up and check the obelisk. When you are done, go back onto the transporter, then use the left transporter. With Klarth/Claus, go up and summon Ifrit, go down and summon Gnome, go right and summon the Sylphs, and go left and summon Undine. When you hear the voice, go back to the transporter.
You are about to fight a boss. In the room with the two transporters, you won't be attacked, so fill your food sack and walk around until you are healed up. Or you can leave Moria to heal up and buy supplies.
For the upcoming battle, set Cless/Cress to use his best skills (e.g. Tiger Teeth and Mecha Blade). Turn off Klarth/Claus's spirits except Undine, and turn off Arche's spells except Thunder Blade. Mint's tactic should be Value HP over TP, but you should also use Gummies to supplement her healing. Arche and Klarth/Claus's tactics should be to Cast Many Spells and Call Many Spirits.
When you are ready to fight, go to the obelisk.
Maxwell uses a powerful Molecular Attack. You might need to use Gummies to supplement Mint's healing. Cless/Cress can't hurt Maxwell during a Molecular Attack, but Klarth/Claus and Arche's spells will stop that attack and make him vulnerable to Cless/Cress's attacks again.
Moria Treasure Room
Go up to reach the next room. Go up and you will automatically open the top left three chests. After that, open the rest of the chests. From top to bottom, left to right, they contain a ?Rod that becomes a Rune Rod, which you should equip on Mint now; a Rune Bottle; 6000 gold; an Hourglass; Elixir; Black Onyx; Verbena; ?Armor that becomes Mithril Mesh, and another ?Armor that becomes Mithril Mesh. Equip one of the Mithril Meshes on Cless/Cress and equip the other on whichever character has the lowest defense.
Go back the way you came. In the room with the flames, pull the lever to extinguish the flames and run across where they were. Then go up and left, and go up through the door. From there, go up through the open door, then go left, and finally go up the stairs and keep going up until you reach the first floor.
You should now go back to Alvanista castle and speak to Runeglom/Lundgrom in the Magical Research room.