We don't have any upgrades to collect between now and the next dungeon, use your Magic Mirror to return to the Light World in the Lost Woods. Before heading to the next dungeon, you should at least go back to the Waterfall of Wishing to get more green potion. One bottle should suffice.
Use your flute to reach #8, southeast of Lake Hylia. Avoid the octoballoon and get in the water, swimming west to the lake. Swim to the center and jump up on the dock at the Pond of Happiness cave.
Now, if you used a fairy in the Skull Woods Palace, go inside the cave and bomb the wall to the right of the pond (if it's not already) and catch fairies in any empty bottles you have left.
Then go back outside and lift the black rock to reveal a Dark World warp. Step on it to find yourself inside an icy structure with stairs leading down, and a pikit hopping around. Go down the stairs, into the dungeon.
Remember that you can freeze an enemy with the ice rod, then smash it with the hammer to get a magic jar.
Stand in the path of the skeletal ice monster (Freezor) on the left and it will come out of the wall and attack you. Touching it will take four hearts away from you, so stay away. Melt the creature with the Fire Rod. The Sahasrahla tile just tells you to use the "magic flames", i.e. the Fire Rod. Move on to the next room.
There is slippery ice on the floor here; take caution. Use your hookshot on the Bari; one of them holds a key. Grab the key and unlock the door to go downstairs.
This seemingly empty room hides Zols that will be revealed as you walk down towards the switch. Step on the switch, killing the newly-revealed Zols, and go east through the door.
Several blocks block your passage. Push the center block to the right and exit through the south door. Several green Pengators attack! Quickly move to the left so they don't attack from all sides. Carefully kill them all, then open the chest for the compass. Exit north to the block room.
Push the center block up, and press the switch to the east and go through the east door. More Pengators attack. Kill or avoid them (using Magic Powder on the bubble to create a fairy if you get hurt), then lift the bottom skull for a switch to open the doors. Go west, back to the room with the blocks.
Push the center block left, stepping on the switch on the way, opening the north door, which you should go through. Get the red Bari out of the way and hit the crystal switch. Then drop a bomb next to the crystal switch and go up to the top of the room, so you're on the other side of the blue blocks when they go up. Once the orange blocks are down, bomb the cracked floor, and drop in.
Two stalfos knights are hiding in the corners of this room. They will fall down from above. To defeat them, hit them with your sword, then put a bomb in its collapsed bones to destroy it. (Sahasrahla will tell you as much.) Once they are gone, proceed to the next room.
The floor will be slowly moving left and right, randomly. From where you enter, if you don't move, the floor won't move you. When you are ready, carefully make your way around the spikes, killing the blue Bari to find a key in one of them, and watching out for the black creatures that come out of the holes (the hole will sparkle before it is about to come out). Make sure the crystal switch at the end is orange. Exit through the locked door below.
With the orange blocks down, you can make your way around the winding path, lifting skulls until you find a switch. Step on it to open the door, and make your way around to it to exit.
Careful of the Zols in here; simply go down the stairs (the skull hides a magic jar).
Kill all the Pengators to open the door. To avoid getting hurt, move to the center of the room so the Pengators aren't all trying to slide into you. Exit.
Stay in the doorframe to avoid the oversized spike trap. When it retracts, exit west.
Make your way past the spinning flames and go down the stairs (the slippery floor makes it hard to get in the right position to go down the stairs, so be patient). On the next floor, melt the two freezors that attack (the center and right-hand ones) and a chest appears containing bombs. Put a bomb down on the floor above the stairway to open a hole, then drop in.
You land in front of the big chest, but without the big key! You'll just have to push the blocks out of the way and exit east for now. Simply go through the next room, avoiding the Freezor.
Get out your Magic Powder and sprinkle it on the bubble when it comes towards you to turn it into a fairy. Go straight up from the door and pick up the skull just above you (the bottom of a group of three in the top-left corner) to find a small key. To make life easier, wait for the black monsters and spinning flames to pass, then use your hookshot on the top-left skull to get across. Pick up the skull, then use your hookshot on the top-right skull to get across. Pick it up to find the switch that opens the door. Exit south.
Carefully make your way across the narrow, icy path, avoiding the spinning flames. Wait for the flames to be pointing straight up to go past them. Exit west.
Pick up the skull at the bottom of the room and step on the switch to reveal a chest. Open it for a small key. Kill the Bari and go upstairs.
In this room, the bottom skull hides a yellow swirly thing that will turn you into a bunny, so don't pick it up. Many Zols will come out of the floor and attack, and the Freezor in the upper-right corner will come to life. Get past the enemies and go through the locked door.
Kill the nearby Pengator by throwing two skulls at it from behind the spike traps. Then, staying a little right of the center of the room, make your way north, and the other Pengator shouldn't bother you. Avoid the spinning flames on the way. Above, Sahasrahla will just tell you not to use up all of your magic if you don't have green potion, and will tell you to "get ready to go into the depths of this dungeon". Okay... Exit at the top-right. Kill whatever red Bari you can, and cross the gap with the hookshot. Exit south.
You will have to bait the giant spike traps in order to get past. Stand in the path of one then quickly retreat as it comes flying at you, then go past it as it retracts. You don't need to deal with the bottom two traps. Go up the stairs.
Kill the blue Bari with the hookshot, then get across the spikes by using the hookshot on the skull to pull you across. Go up the stairs on the right side of the room.
As you go in, a stalfos knight drops in, so kill it as before. Hammer the pink things to lift the heavy block, then throw it quickly and try to avoid the spinning yellow thing that turns you into a bunny. (Stand in the left corner near the stairs leading down, and the yellow thing should hit the wall.) Collect the small key and pound the next pink things into the ground. Kill the next stalfos knight, then pick up the bottom-left pot below to reveal a switch. Step on it and a chest appears. Get it for the dungeon map. Then go over to the statue and pull its tongue (!) to open the door in the east wall. Go through.
Go up the stairs and pick up the pots to access the chest below, which contains the big key! Ignore the blocks to the left and go back downstairs, pull this statue's tongue, go through the door and down these stairs.
Lift the skull below to reveal a switch. Step on it to reveal a chest on the other side of the spikes. Use your hookshot to pull across to it, and open it for a small key. Go through the locked door in the west wall.
You're back in the room with the giant spike trap. Bait it, then exit through the west door. Go down the stairs in this room again, then bomb the floor above the stairs to open a hole again (trying not to get in the path of the center Freezor). Drop in to find the big chest (again) and open it for the Blue Mail! Now your green threads are replaced with a blue tunic and yellow cap. Not very color-coordinated, but oh well. Damage from enemies is now reduced by half! Push the blocks to get to the next room.
Go through the big key door, killing the Freezor on the way. There is a stalfos knight in the center of the next room, so kill the Bari from afar with the hookshot and then approach the center to make the stalfos knight fall. Kill it, then open the locked door above, and go down the stairs.
Avoid the bubble as it approaches (or sprinkle Magic Powder on it), then exit through the south door, where a stalfos knight falls from above. Kill it as usual. You can kill the blue Bari if you wish; the Freezor in the upper-left corner will come to life, so be careful. If you lift the skull you find a switch that won't stay down. There's nothing to put on it... Go through the locked east door and hit the crystal switch (use your hookshot or boomerang; you should hit it from a distance). A spinning yellow thing will appear, so get away from it. Pick up the skulls if you want. Then go to the last room, through the north exit, up the stairs, south through the door, and you find the blue blocks are down and the orange blocks are up.
You need to push one of the left-hand blocks, and now you can't because of the orange blocks in your way. Unfortunately, you have to go around the dungeon to get to the left side of the barrier.
Exit through the east door, where you must pick up the top-right skull for the switch to open the door. Exit south again, and continue on the linear path until you reach the long room with the icy floor, Pengators, and spinning flames. Lift the the leftmost bottom-right skull to find a switch, which opens the door to the left. Go through it and fall down the hole to get to the room with the big chest. Exit east to find yourself in the room with the hole in the center. Kill the Freezor that pops out, then push the bottom block right, and drop in after it.
Kill the Stalfos Knight again, and pick up the skull to reveal the switch that won't stay down, then push the block down onto it to make it stay down! Exit south.
Kill the red Bari. Don't bother picking up the big block on the right side of the room; it hides four yellow swirly things! Leave it alone, and pick up the two skulls at the left side of the room. Pull the right-hand statue out of the way, and pound down the pink things. Lift the heavy block to reveal a hole. If you are ready for a boss fight, drop in to find yourself face to face with...
-- Kholdstare --
This giant snowball is frozen in ice. Blocks of ice will fall from the ceiling, breaking into four pieces either diagonally or straight out. You must use the Fire Rod to melt the ice in which Kholdstare is encased. After hitting the ice 8 times with the Fire Rod, it will melt, and Kholdstare divides into three snowballs that slide around the room. Be careful; touching one of the snowballs will take away three hearts (or six if you didn't get the Blue Mail for some reason). You can use the Fire Rod on the snowballs, and use your green potion once you run out of magic, or you can just slash the snowballs with your sword. The Fire Rod will kill them pretty quickly, so just one bottleful of green potion should be enough to finish the battle.
Once the last snowball is destroyed, step forward into the explosion to get the heart container, then move to the center for the crystal!
The maiden inside speaks of the mysterious powers of the Hylian people and the seven wise men. The blood of the Hylia has thinned over time, and even the seven maidens' power is not strong anymore. The courage of the Knights and the wisdom of the wise men together will increase the maidens' power. If you defeat Ganon, the Dark World will disappear and the Triforce will wait for the next person to touch it. Your hearts and magic will be filled, and you will be returned outside of the dungeon.