After visiting Eyeglass Lake, go to Subrosia and get the Bomb Flower and use it to enter the tower of Autumn. With the power of Autumn, go to Unicorn's Cave north of Eyeglass Lake.
Reveal a Magnet
From the entrance, go north, then east. Go into the first mine cart. If the track is bent, hit the switch so you go north. When it drops you off, go up the stairs and around the path to exit east. Kill the Darknut and push the block to make the N magnet appear.
Get a Key
Go back to the room with the two mine carts and go into the cart on the right. Hit the switch on the way. When it drops you off, get the key from the chest.
Get the Dungeon Map
Get back into the mine cart and hit the switch. When it drops you off, go back into the cart. This time you should end up in a room with some stairs. Go down the stairs.
Go west and use the Roc's Feather to make your way through the room. Ignore the cracked stones for now and go up the ladder.
Exit east and kill the Gibdos and Gel. Open the chest to get the Dungeon Map.
Get the Magnetic Gloves
Go west twice. Go to the left side of the room and push the outer blocks up and the middle block to the side. Go north, then unlock the west door and exit west.
Open the chest on the platform to get the Magnetic Gloves. You can use these to pull N magnets toward you, or to pull yourself toward S magnets. Each time you use the gloves, it changes the polarity. The glove will say N if it attracts N magnets and repels S magnets. It will say S if it attracts S magnets and repels N magnets.
Get 100 Rupees
Use the gloves in S mode to pull the N magnet toward you and pull or push it onto the switch to open the door. Exit east.
Go south, then push the outer blocks down and the middle block to the side. Go back to the room with the stairs and go down.
In the underground area, bomb the cracked blocks and go west. Use your shield to block the fireballs from the statues, and jump onto the moving platforms to reach the ladder on the west side. Go up.
The statues in this room move opposite to each other. If you push the statue down, the other one goes up. If you push the statue left, the other one goes right. Push the statue down three times, right twice, and up once. Exit south.
Go around the path and exit west.
Go to the left side of the room and open the chest to get 100 rupees. From this room, exit north.
Get a Second Key
Kill all of the monsters in this room. You can use the magnetic gloves to pull the masks off of the iron masks. The owl statue says "Recall the order you slay the knights in."
Exit west after getting rid of the moldorms and iron masks. There are four Armos Knights in this room. Be sure to remember which order you defeat them in. After they are all gone, open the chests in the order that you defeated the knights. If you do it correctly, you get a rupee, ten bombs, four ember seeds, and a key.
Get the Compass
Exit east, then south. Use the Magnetic Gloves to pull the N magnet out of the way. Exit south.
Kill the Moldorm and Iron Masks and exit west.
Carefully go around the conveyor belts to reach the chest in the center, which contains the compass. You can also use a pegasus seed and use the Roc's Feather to jump from the entrance to the center. However, you have to go the long way back, or just fall into a hole to be sent back to the entrance.
Get a Third Key
Exit east from the compass room, then south twice. Stand on the orange tile and use the Magnetic Gloves to be pulled onto the S magnet on the left side. (Use the gloves in N mode to be pulled to the S magnet.) Go north and get the key from the chest.
Get a Fourth Key
Go south and stand to the right of the S magnet. Use the Magnetic Gloves in S mode to be pushed to the right side of the room. Exit east, then north, then east. Use the first mine cart but don't hit the switch. You should end up in a room with a spinning S magnet in the middle.
Use the gloves in N mode to be pulled onto the S magnet. Wait for it to turn you in the direction of the left side of the room, then quickly let go of the gloves button and press it again to use it in S mode and be pushed to the chest on the left. Open it to get a key. Go back to the east side of the room using the S magnet and get into the mine cart.
Get a Fifth Key
When the mine cart drops you off, go into the mine cart on the right. If it's not there, you can go all the way back to the room with the statues that moved opposite to each other and go down the stairs, then go east to the farthest ladder. Or you can just save and quit, then start from the entrance of the dungeon and go north and east.
Get into the rightmost mine cart. You want to go to the right, so hit the switch if the tracks are going straight up.
When the mine cart drops you off, go to the right and stand below the S magnet. Use the gloves in S mode to be pushed across the gap. Get into the mine cart on the left. When it drops you off, open the chest to get a key. Get back into the mine cart.
Go east from where the mine cart drops you off and unlock the east door. Exit east.
If Syger rolls toward you, jump over him with the Roc's Feather. Hit the ball on the end of Syger's tail until he dies.
Get the Boss Key
Go north from Syger's room, then exit east. Step on the switch in the north part of the room and go through the northeast door.
Avoid the beamos and exit west. Use the Magnetic Gloves to attract the Magunesu enemies toward you. Kill them with your sword, then exit west.
Use the Magnetic Gloves to move the N magnet in front of the flames. Now go back to the room with the key block. Unlock the west door and exit west. Use the Magnetic Gloves to pull the N magnet onto the switch. Exit north. If there is no N magnet in this room, go back to Syger's room to warp to the entrance, then go north and east to reach the room with the two mine carts. Get in the left one, and make it go north. Go up the stairs and around the path to exit east. Kill the Darknut and push the block to make the N magnet appear.
Go back to Syger's room and go north, then west. Use the Magnetic Glvoes to pull the N magnet onto the switch. Exit north.
Use the N magnet to shield yourself from the flames and go to the northeastern corner of the room. Unlock the door and exit north. Go down the stairs.
Go down the ladder and use the Magnetic Gloves to be pulled to the magnet in the ceiling. Jump onto the moving conveyor belt and jump to the ladder on the left side of the room. Go down. Jump onto the moving conveyor belts and go to the right side of the room. Use the Magnetic Gloves on the magnet in the ceiling to reach the Boss Key.
Reach the Boss
Go back upstairs. Exit south and once again use the N magnet to shield yourself from the flames. Exit south, then east. Go to the key block on the right side of the room and unlock it. Go down the stairs.
Jump onto the moving platform. If you fall to the spikes, use the Magnetic Glove to push away from the S magnet in the floor and get back to the ledge. Use the ceiling S magnet to get to the platform on the left. Exit west.
Drop to the ledge down below, then use the Magnetic Gloves to push away from the S magnet and reach the upper ledge. Jump to the ladder and climb up.
Lift the uppermost pot and use the Magnetic Gloves to pull yourself toward the S magnet up above, but stop using the gloves when you are over the ledge. Turn right and use the magnetic gloves to be pulled to the S magnet on the right. Walk to the top of this ledge and use the Magnetic Gloves to be pulled to the platform in the middle. Unlock the boss door and go through.
Use the Magnetic Gloves to push and pull the spiked ball around. Hit Digdogger repeatedly with the spiked ball. It eventually splits into smaller Digdoggers. You can kill these with your sword or with the spiked ball. Repeat the process until you have defeated Digdogger.
Get the Essence
Go north to get the Nurturing Warmth. The Maku Tree says that he saw a vision of you in vast ruins. He is referring to Tarm Ruins.