With Anjean tied up dealing with her former student Byrne, Zelda realizes that we will have to find the Sage of the Fire Realm on our own. So let's get back on the train and set a course for the Snow Realm so we can travel the path leading to the Fire Realm. The tracks in the Tower of Spirits will rotate for us so that we can get underway. As soon as we enter the Fire Realm, Zelda will note that its volcano is spewing hot rocks, some of which will fall right on the Spirit Tracks in front of us. Use the cannon to blast them away as we plot our course eastward to Goron Village. There are Dark Trains roaming around on the tracks north of us, but don't worry about them until later.
Once we reach Goron Village, head north and we will see some Gorons gathered around a passage that's blocked by hot molten rock, which means that we can't get access to the rest of the village either. Talk to one of the big Gorons, and he will tell you to go talk to Kagoron, who is at the altar of the mountain goddess. To get there, head up the two stairs going to the path heading west. Continue going west until you see a path to the north where rolling boulders are coming down. Time your passing the boulders so that you can reach the stairs to the left and then go south until you reach another path with rolling boulders blocking your way. Again time your passing them so you can go to the left and then south.
You will now reach a lake of lava that you'll need to cross. Near you to the east is a switch orb, and to the west are two posts that will let you whip-swing to a mesa at the north. Hitting the switch orb will cause a bridge to appear crossing the lava lake going east from that mesa to another one, but this is timed, so you'll have to get across it before time runs out. To get there before it does, have Link stand near the posts and use the Boomerang to hit the switch orb, then quickly switch to the Whip to whip-swing north so you can get across the bridge before it retracts. Now simply head north and you'll be at the altar where a dark-skinned Goron named Kagaron is standing. Talk to him and he will tell you that only the elder of the village would know about the Fire Sanctuary, but in order for us to meet him we'll need to do something for him. He will tell Link to meet him at the bottom of the mountain, so go back south, but head to your first right until you see some posts to whip-swing to the east. Over there is a treasure chest which contains a pearl necklace. Then head straight south and leap down, then continue heading east, having avoided going through passing the rolling boulders.
Once you've reached the village, Kagaron will appear to tell the big Goron that he wants to give Link a freight car for the train. The Goron will then push the freight car onto the tracks until it is hitched up, which gives us a new useful addition for traveling. Kagoron will now ask us to bring back something cold to cool the lava from one of the merchants in the nearby villages. Zelda knows where we can get something cold enough to do that, and that would be from the nearby Snow Realm.
Transporting the Mega Ice
Now with our freight car installed, let's travel westward into the Snow Realm and plot a course for Anouki Village. As we enter that realm, we will have new enemies in the form of pirate tanks lobbing cannonballs at us. Peg them with some cannonballs of our own to stop them dead in their tracks. At Anouki Village, talk to Honcho about ice, and he will tell you about their product called Mega Ice. He will direct you to the Anouki standing near a lake on the west side of the village who is the maker of that product. Go to him to talk and he will ask you to give him a lift because the lake in the village has been polluted with Chuchu slime. He needs a fresh supply of cold water so he can make the Mega Ice for us. The only other place we remember seeing a lake in this region is Wellspring Station, so agree to give him a lift and he will wait for us on the train. Safely transport him to Wellspring Station, and he will give us a Force Gem for our troubles, which will open up some new tracks in the Snow Realm. He will tell you that the making of Mega Ice will take some time, but all we have to do is go into Ferrus' house and then leave, and instantly we'll have our Mega Ice ready. He will charge us 25 rupees for the service and will load it up on the freight car. (If you think paying him 25 rupees for the ice is a bit too steep, you can haggle with Noko to lower the price until he gives you the Mega Ice for free!) He will also warn us not to get hit or swerve suddenly, which will cause the ice to spill, and that while the ice won't melt in cold areas, it will certainly begin to do so in warmer areas.
With our cargo on board, let's plot a course back to the Fire Realm from Wellspring Station. As we reenter that area, we notice that not only is the ice beginning to melt, albeit rather slowly, but also there's a Dark Train that's blocking our direct route to Goron Village, so we'll have to go around to where the Dark Trains are patrolling the upper routes, being careful not to run into them. If all goes well, you should be able to get the Mega Ice to the village long before it turns into a puddle. Talk to Kagaron after you have stopped at the station, and he will get the other Gorons to bring the Mega Ice over to the molten rock. With that cleared out of the way, we can now go into the village itself.