This part will take you through the entire Arbiter's Grounds.
Inside the Arbiter's Grounds
The first few rooms
As you go down the staircase into the first room, you'll notice that it has shifting sand and some sand whirlpools, as will most other rooms in this dungeon. The shifting sand will cause Link to slowly sink the longer he is in it, until he is in too deep that it sucks him in, costing him one heart in the health meter and causing him to restart the room he is in. The sand whirlpools will instantly suck Link in, also causing the same amount of damage.
We want to get to the gate that is on the opposite side of the room. First off, take care of the Moldorms that will swim through the sand and then jump out to attack you: lock onto them when they close and then use the Clawshot to pull them out and strike them dead. Next, aim for the Clawshot target on the wall to your right above a stone platform so you can drop onto it. Then hop across two platforms going to the left near a sand whirlpool, then go across two platforms heading back to the right, watching out for the one in the middle that will start to sink when you land on it. Now go across the sand to a fenced-off area on the left where you will find a chain near some shifting sand. Latch onto the chain with your Clawshot to pull it towards you, then grab it and pull it out. This will cause the gate to open. A group of small Stalfoses will emerge from the sand in that corner to attack you; strike them down with the sword.
Now head for the gate and go up the incline toward a locked door in front of you and two other doors on either side. The one on the left will contain an urn that you can refill your lantern with oil, which you're going to need soon. The one on the right has wooden bars you can slash through with the sword. Go all the way across to the treasure chest and open it to get a small key. When you do, you'll see a swarm of small insects called Poison Mites gather toward Link and crawl onto him. These will not hurt Link, but they will slow up his movements. A simple spin attack should shake them all off when you're bogged down by them. Once you have the key, go to the locked door and open it.
This will take you into a really dark room where you're going to need the lantern to see your way around, because it has lots of shifting sand spaces to watch out for. Also in here you'll face a group of mini-Stalfoses that will surround you, so take them out with a quick spin attack. Light the two torches that are near the other door to raise the metal gate in front of it.
The first Poe
Go through the door into the next room where you'll see a gate close down in front of a large door on top of some steps, and some lanterns will float around four braziers and steal the flames from them. The lanterns will then circle around Link for a bit, and then only one of them will appear in front of him. Change into wolf form and use your sense mode to see that it is a Poe. To strike it down, target it and watch for it to turn bright, indicating that it will attack you, then attack it before it has a chance to do so. Do this two times to put the Poe down to the ground so you can jump onto it and rip out the Poe Soul. Its lantern will explode, and the flame it stole will be returned to one of the four braziers. Now stay in wolf mode and sniff the odor that the Poe produces. With its scent learned, you can track down the other three Poes in this dungeon.
The second Poe
The Poe scent will lead you to something buried near the wall to the west. Dig through the sand to reveal a chain that you must pull on to cause a staircase to appear, leading you to a room one floor below you. Go down the stairs into that room where there are two bat-winged skulls called Bubbles flying around. Knock them down to destroy them, then turn the handle at the pillar in the center of the room to shift the walls around so you can enter an alcove with a treasure chest and a ReDead guarding it. Attack it quickly before it stuns you temporarily by looking in your direction, then open the chest that will give you a small key. Now transform into Hylian form and aim through the hatch in the ceiling for a target to Clawshot your way into the room above you. Strike down the rats that are in this room, then go through the door you can access to enter a room where your next Poe to hunt down is located. You'll find the Poe hiding among the lanterns hanging on the wall if you use your sense mode as a wolf. Again use the same strategy that you did on the first Poe to defeat him. His lantern will explode, and as you return to the room with the gate, its stolen light will return to one of the four braziers.
The third Poe
Return to the room with the handle near the pillar and turn it again so you can exit the room and go back to the room with the four braziers. Now go to the area to the right of the stairs, passing quickly over the shifting sands, to open the treasure chest that contains the Dungeon Map. (The treasure chest on the other side of the stairs contains a Piece of Heart.) Then head for the door that will take you back into the room above the one in the basement and pass through it to reach the locked door we can now open. In the next room, cross over the platforms to your right, making sure you avoid getting stopped by spiked barriers that will pop up and block your way, costing you some time. At the walway you'll reach, pull the big block out toward you until it falls into a track, then push it so that it will give you a clear path between two platforms. Climb up onto one of the platforms and grab the chain nearby to pull it as far as you can go to raise a chandelier that's over a bridge to your left. Once it's lifted as high as it can go, let go of the chain and then quickly run across the bridge before the chandelier drops down on top of you. Past the bridge, go up to the top of the stairs, slaying the Bubbles that are flying around there, and go into the alcove straight ahead to open the treasure chest that contains the Compass. Then turn the handle near the pillar in the center to shift the walls around, giving you access to two other passageways. One will lead into a room with a ReDead guarding a treasure chest that contains a small key. The other will lead to a locked door that you can open with the key you've just collected.
Go through the locked door and you'll enter a winding passageway with shifting sand patches and mini-Stalfoses that will come straight at you from two ReDeads that are right around the corner. Smash your way through the mini-Stalfoses, then change into a wolf and take down the two ReDeads, being careful not to be stunned by them. At the point where you met the ReDeads you'll see an Poe scent trail that will lead you to something buried in the sand near a wall. Dig at that point to uncover a chain you can pull to make a nearby wall move. Behind that wall is the third Poe to hunt down, using the same strategy as you did before with the other two. Its lantern will explode, and its stolen light will return to one of the four braziers when you reenter that room.
The fourth Poe
Continue forward in the passageway until you reach the door, then enter a circular room with a small alcove to the right that has a treasure chest you can open for a small key to open the locked door in this room. Once you get the small key, however, the lighting will turn dark, and you may notice that Link is starting to move very slowly. Change into wolf form, and you'll see Midna reacting to something attached to Link. Go into sense mode to expose what's causing Link's slowdown and Midna's reaction: Ghoul Rats have appeared and are latching onto Link. Do a Midna-charge to get rid of the rats that are attached to you, then attack the remaining ones before they latch onto you. The lighting will remain dark in this room after the last Ghoul Rat has been disposed. Now open the locked door and you'll see you're on a balcony above the room with the braziers, and that you can hop onto the chandelier in front of you to reach the other balcony where there's a door to open.
Past that door, go to the stairs on your left and drop down to where there's a block we must push forward to connect a path between two platforms leading to a bridge being blocked by a fallen chandelier. Climb up onto the platforms and grab a nearby chain to raise the chandelier as high as it can go, then let go of the chain and stop in the middle of the bridge so that when the chandelier falls, we will be in the middle of it. Then climb up on the chandelier so that we're facing the door to the east and jump across the shifting sands to the ledge near the door.
Go through the door and enter a circular room where we see a metal gate drop in front of the other door, then a Stalfos warrior will arise to attack you. You can do a Back Slice roll to get behind it and strike it down with the sword, but it will only arise after a while. You're better off using a bomb arrow to get rid of it completely. The metal gate in front of the other door will be lifted, and you can proceed up the stairs to the next room with five lanterns behind one lantern on the other side of a shifting sand patch. We must light the lantern in front of the other five lanterns first, then light one of the other five lanterns to open a panel on the west side of the room that hides a door. The lantern we want to light is the one that's the closest to that panel; if we light any of the other lanterns, it will cause a swarm of mini-Stalfoses to come toward us, which we will have to strike down before trying again.
Go to the door behind the panel and you'll enter a circular room with lanterns hanging around the walls. Go into wolf form and use your sense mode to expose the last Poe hiding out among the lanterns. This Poe will then split into four copies of itself and then circle around Link until the original attacks him. Watch the copies and wait for the original to attack, which you can see when it turns bright and the copies fade, then attack it before it attacks you. Repeat the same strategy one more time, then jump at it to rip out the Poe Soul, causing its lantern to explode. A door will now open to lead you back to the one with the chandelier over the bridge with the shifting sands. Aim for the Clawshot target near the door that leads back to the room with the four braziers. With the last stolen light returned, the gate will now open, and we can proceed onward.
A few more rooms
Past the gate is a circular room with two doors leading to other rooms. The door to your right leads to one with the Big Key, but there's a sand whirlpool blocking our way to it, so we'll have to wait until later to get it. The door to your left leads to a long circular shaft with a handle next to a pillar that causes the floor to rise or lower one level depending on which way you turn it. Slay the Bubbles that are in that area, then turn the handle to go up two levels to reach a treasure chest with the small key; however, as one door will have spikes blocking you from reaching it, go through the other door to get to the treasure chest. Then turn the handle to lower yourself all the way down until you reach a level where you see the locked door you can now open.
The next room is a maze of spikes and shifting sand patches, with Ghoul Rats to harass you. Go to the left side of the room, cross forward over the sand patch, then go to your right across another sand patch, then go forward again until you reach the right-side corner next to the covered walkway. Pull on the handle to get the gate inside the walkway as far out as you can. Then quickly cross over to the left side of the room and then through the gate before it closes. Watch out for the ReDead in the other corner, because he will stun you if you get too close to him. Go through the passageway on your left when you're past the gate, but in addition to shifting sand patches you'll also have rolling spikes on the side to avoid getting hit by. When you get near the door, go to the right first and break open a jar to release Ooccoo who will help you again by transporting you out of the dungeon.
Go through the door and make your way past the rotating spike log to the door across from you, entering a room with some Stalfos warriors coming to life. Destroy them with a bomb arrow, then roll across the sand patch to your right to take down another Stalfos warrior. This will open up a gate at a door where the rotating spike log is. Go back through that area to get past the gate, then prepare for an uphill climb up some platforms that will sink into the sand when you stand on them. Also you'll have those annoying Poison Mites that will cling onto you to slow you down, making going up the incline difficult if not impossible. Then jump across the gap and go up the stairs to your right to open the door just ahead of you.
In a dark room, Link will see a black sword being held down by ropes. Cut one of the ropes, and the sword will seemingly come to life and start swinging itself with the intent to kill you. Go into wolf form and use your sense mode to see that it's a ghostly being called Death Sword wielding the sword. Wait until it glows, which indicates that it will attack, then jump on the ghost and attack it. It will then be visible in our normal sight, where it will float around us for a bit before sending out a few energy bolts to hit us. Return to Hylian form and aim for the head with your arrows. This will send the ghost spinning around the room until it stops, where you can give it a few good sword strikes. It will then go back to floating around you again to strike you with energy bolts. Repeat the same strategy of hitting it with an arrow, then waiting until it lowers itself to the ground to give it some sword strikes. It may turn invisible again, requiring you to go back into wolf form to see and attack the ghost to make it visible again. When Death Sword is struck enough times, it will writhe and then scream in agony before it vanishes. This will raise up a gate in front of the door to the north that will take you into the room to get your next useful item -- the Spinner. This acts as both a vehicle for Link to ride on and as an offensive weapon for something we'll encounter later on in this dungeon.
The big key
To try out the Spinner, go to either of the rails on the sides of the room and activate it; this will allow you to ride along the rails until you either jump off or reach the end of the rail. When you do jump off the rails, the Spinner will remain active for a short while before it slows down and disappears, or you can deactivate it. Head back to the door to take you into the room before Death Sword, then ride the rail on the left side until you reach the sand patch, then jump across and ride the rail on the right side. This will take you up to a door that will lead you to a room full of rails to travel on, which will require a lot of jumping from rail to rail. First ride the rail on the left, then jump to the rail on the right, then to the left, then to the right, then to the left until you're past the circular rails with the rolling spikes on them, then to the right. This rail will take you up to an area with a rolling spike log and a Stalfos warrior to destroy, plus a treasure chest that contains a Piece of Heart. Ride the rail to the right of the treasure chest, being careful not to get hit by the rotating spike log, then jump to the rail on the right, then to the left and ride it until you reach a rail loop near a sand patch, making sure you're riding it to the right and not to the left to get out of the loop; you can jump around from side to side to switch directions. Where the rail ends, go to the right up an incline until you see two rails close together on a bridge with rolling spikes moving on both rails. Here is the tricky part: you must carefully switch from rail to rail to avoid the spikes or else you'll get knocked down and have to try it again. This will take you up to a door where, behind it, is the room with the Big Key in the treasure chest. Now we can ride the rails on either side of the room to leave it.
The boss chamber
We're back in a previous room we've been through that you may have noticed a hole in the ground that requires us to insert something into it. We have that something to put into that hole, the Spinner, so activate it when you're standing over the hole and keep pressing the B button to rotate the Spinner around and around. This will eventually cause the walls of the room to spin, revealing a chamber with a large sand patch, a pillar, and a spiraling rail path going to the left. Ride the rail up until you're high enough to jump off the rail and onto the top of the pillar, where you can insert the Spinner into a hole and spin the gears around until you see two flames on the pillar ignite and another spiraling rail path to take. Ride that rail until you reach the Big Key door and open it to meet the dungeon boss.
Arbiter's Grounds Boss: Stallord
In the next room, Link sees a giant skeleton at the bottom of a pit. As he goes down to take a look at it, Zant will briefly appear and congratulate Link for staying alive this long before he makes a dark sword appear and plunges it into the skeleton's head, causing it to come alive. This is the dungeon boss Stallord, also referred to as Twilit Fossil.
In the first part of the battle, Stallord will focus on moving his upper body around the center of the pit, using his arms and his fiery breath to attack you. What you want to do is ride the Spinner around the outside of the pit until you can get behind Stallord to launch yourself toward him and attack his lower vertebrae. Making this difficult, besides Stallord's moving arms and fiery breath, is that he summons up Staltroops that will act like pinball bumpers to prevent you from getting close to him. Also, don't stay on the outer rail for too long, because there are rolling spikes that will knock you off the Spinner.
When enough of Stallord's lower vertebrae has been knocked out, his body will sink into the sand, and then the sand will empty from the pit, leaving just his head. Go over to the spot in the center of the pit where you must use the Spinner to rotate some gears, which will cause the center part of the pit to rise up, giving you other rails to ride on. Stallord's head will come alive and then push Link down into the pit, and here the second part of the battle begins. Link must ride the Spinner on the rails until he gets close enough to Stallord where he starts breathing fire at you. When he does, jump over to the other wall. Do this until Stallord is very close to you, then attack his head. He will fall down into the pit and be immobilized, allowing Link to strike the sword in his head. He will then rise and have us chase after him again on the rails, only this time there are rolling spikes we need to avoid on the center wall. In the third chase the rolling spikes will appear on both the center and outer walls. Avoid them by jumping from side to side as you get close enough to attack his head. After the third successful strike, Stallord's head will hurtle for a bit and then explode, releasing the sword stuck to his head that will also explode, giving you a Heart Container. A bridge will now appear and a gate will open that will take you to the Mirror Chamber.
You have completed the Arbiter's Grounds. Collect your Heart Container, and enter the gate to leave the dungeon. You will be asked to save your game at this point.