Getting the Bow and Arrows
The first corridor has some Fire Keese. Defeat them with the Boomerang. Turn left at the blue door. Go north. Slowly navigate through the spikes and flames. Go south and you'll face three Stalfos. To defeat these, walk near them, then attack them until their heads fall off. Attack the head to kill. Go through the blue door. The sign says, 'The pitfalls here mirror those on the other side...' The pitfalls are the brown sections of the floor. Wherever you see one here, black out the opposite area on the other side of the room. Walk around the area to the staircase with the red arrow, and go up. You'll see a small mine cart. Jump in to be carried to an area with a small chest containing a key. Get back into the cart. Go back downstairs, and up the smaller staircase, but don't jump down from here yet. Instead, throw the Boomerang at the purple switch. A small blue platform will drop down. Pick it up and carry it to the right of the locked doors. Drop it on the red crater. This creates a platform that you can cross. Pull the block here back twice, push it right once, up twice, and right as far as possible to block the stream of fire. Go south. Avoid the pitfalls you marked out earlier, and walk around to the staircase with the red arrow (The chest you see contains a Red Potion). Go upstairs.
Jump into the mine cart. Hit the two purple switches you see along the way with your sword. When you land, you'll face another Stalfos. Defeat it, then open the chest for a key. Jump into the cart, and go back downstairs. Go around to the smaller stairs and jump down. Go left and unlock the doors. Stand in front of the blue door and throw the Boomerang at both switches. You need to do it in one go, since there is a very short time limit for hitting both switches. This opens the blue door. Go upstairs. The enemy here is completely armoured. You need to get it to spin into the black balls along the walls. Walk close to it, then run away, towards some of the black balls, and move out of the way as it spins towards you. With correct timing, it will hit the black balls, get stunned, and you can attack it. Do this three times to defeat it, and be rewarded with 20 Rupees and the Bow and Arrows! To use these, hold the Touch Screen where you are aiming, and release to fire. Go out of the blue door and fire an arrow at the eye. It will turn blue and create a bridge that you can cross to the staircase. Go up.
Getting the Boss Key
Fire an arrow at the blue object across the abyss. This redirects the path of the arrow, here towards another one, and on to an eye. This creates a bridge. Cross it, and slash the blue object until it faces north. Pick it up and throw it at the platform to the left. Fire an arrow at it. Cross the bridge it creates, slash the blue object to get it to face left, pick it up and throw it at the platform to the north. Fire an arrow at it to create one more bridge. Cross it and go down the stairs. Go down the next staircase as well.
Inside this room are four Stalfos across some lava. Fire arrows at them to kill them. If you want what they leave behind, throw the boomerang at the prizes. Go south and look left to see a blue object. Fire an arrow at it. This starts a timer during which you can cross the whip posts to the right. When you land, go north-west. Wait for the blue platform to land, then jump onto it. Wait for the next one, and the next one. But on this one, wait for it to go up while you are on it, then jump onto the next one, and onto the ground. Cross the whip posts. Stand on the switch to open the blue door, but don't exit yet. Carefully pass the three switchblades. After the third, wait for the next one to go south, then follow it and turn left. Wait for it to pass, and go right. Throw the boomerang through one of the Fire Keese, and the two torches. This creates a blue platform to the left which you can cross. Cross it and go upstairs.
To defeat the tortoise creatures, fire two arrows at their heads. The chest that appears contains a piece of treasure. Check all the signs. They tell you to hit the eyes above in the order 2, 1, 4, 3. Take this down directly above the signs that tell you the order. Go up the stairs to the left. Go around the area to a switch on the floor. This opens a nearby blue door, but closes it again when you step off. Go north, and pick up the blue object. Drop it near the blue door and face it left. Stand on the switch and fire an arrow at the blue object. A blue platform will drop down. Pick it up and carry it north. Drop it on the crater to the left. Go back and pick up the blue object. Carry it north, jump on the blue platform, wait for it to go up, and jump off. Drop the blue switch, and pick up the blue platform. Drop it on the crater to the left of the pillar. Place the blue object on the crater to the right of the pillar. In the north-east of the room is another blue object. Face it north-east, pick it up, and place it on the crater south of the pillar. Hit the purple switch in the south-east corner. Stand on the blue platform. Fire an arrow at the purple switch north of here. When you are up, fire arrows at the eye and the blue object facing north-east. This opens the blue door. Jump off the blue platform, hit the green switch, go through the blue door, and open the chest for a Small Key. Go back to the area right of the north-east blue object, and jump down. Cross the whip post, and go north up the stairs.
Go left and open the door. Go through to the left, and jump into the mine cart. To the south of the floor you'll see some eyes. Remember the order you took down earlier? (2, 1, 4, 3) This is the order in which to hit these eyes with arrows. So, hit the second eye first, the first eye second, the fourth eye third, and the third eye last. You keep going around in circles until you hit the eyes in the correct order. When you do, the track of the mine cart will change. Go down the stairs where you get off. Go south in the next room, and down this staircase as well.
Look at the map to the left of the stairs. It has a series of stars on it. Record these on the map. These are switches you must hit in order to change the tracks of the mine carts correctly. Go left, jumping across the platforms, to a Bomb Flower. Pick it up and throw it at the large rock to the right of the staircase. It becomes a blue platform. Pick it up and throw it at the crater. Jump on it, wait for it to go up, and jump into the mine cart. Hit the switches in the areas marked on your map to avoid the eruptions along the path. From where you land, go south-west. You'll see the Boss Key. Blow it into the mine cart with the Whirlwind. Equip the Bow and Arrows. Go north and jump into the other mine cart. As you travel, you need to hit the switches marked on the map. Hit the first two with the sword, but the last one must be struck with an arrow. You and the Boss Key will land at the Boss Door. Pick up the Key and open the door, and go downstairs.
Go north. Check the sign to activate the blue portal, break the pots for health and arrows, save your game, and continue upstairs.
Boss: Vulcano (Cragma), Lava Lord
The door will close once you enter. The rock in the centre of the lava will start to glow and come to life as Vulcano/Cragma, the Lava Lord. Avoid his attacks and the meteors that fall. When he rises, fire an arrow at the glowing patch that rises out of the lava. When a large black boulder falls, stand near it, wait for him to attack, then run away. He will break the boulder and create a blue platform. Carry it and drop it on the crater to the north-east. Jump onto it, and into the mine cart. As you travel around him, fire arrows at the glowing patches on his body, and his hands, if he raises them to you. When you are at his eye level, shoot at it to stun him, and reveal his true weak spot. You'll land soon after, so run over and attack his head. He will rise, and you need to repeat the process again. If you need arrows, the meteors that fall often have some. If he gets the opportunity to attack you while in the mine cart, he'll throw you to the ground, and you'll have to start over (any patches already hit will still be gone, though). After two or three attacks on his head he should be defeated.
A pedestal will rise from the lava. The Fire Source will come to rest on it and begin to glow. Energy will flow along the Spirit Tracks to the Tower of Spirits. The Tower of Spirits is finally fully restored! The Fire Glyph/Rail Map will glow, and the tracks to the Tower will appear on it. A chest will appear. Open it for a Heart Container. Step into the blue portal to return to the Spirit Train. Zelda is very worried about Anjean's safety, so hurry back to the Tower of Spirits.