The proud citizens of the mountains. They are known throughout Hyrule for their mastery of steam-based technology and smithing skills. Struck by a deadly flesh and bone rotting disease, they have hidden themselves deep within the carbon mines of the mountain. The cogs were constructed by the ancient leaders of this race.
Link arrives on Goron Mountain to find all the Gorons suffering from a tooth-rotting disease. Mining operations and production of manufactured good have stopped completely, and all the Gorons merely sit around on the mountain, weakened from malnutrition and depressed since they can't do basically anything.
Link finds the Goron Elder, Gor Indigneo, ensconced back in his chambers. Upon entering, he is angry to see a mere Hylian has gotten in, and demands what Link wants. Upon hearing Link wants to search for the Earth Cog, Gor Indigneo gets even angrier. He explains the problems the Gorons have: their teeth have been rotting ever since they discovered the Violet Ore, his people are weak because they can't chew rocks, they have to eat mud soup made from mushy ore mined down the mountain. My people are eating mush! There's no calcium in mush! The Gorons are strong people, and maybe could get through this, but the worst thing of all is that the Gorons are all so depressed they're beginning to give up hope that anything will ever get better. The last thing we need is some Hylian trying to find some ancient artifact when we're trying to deal with our own problems! I can't help you until my people's happiness is restored! Guards, take him away! The Guards rise slowly, pause for a moment, then sit back down, too weak to do anything. "See what I mean? Get out of here!" the elder screeches.
Link wanders around the city, and talking to the Gorons, two or three mention that they miss the old days, before there were problems, when the simple pleasures were watching a good Goron wrestling match. The old wrestling arena sits decrepit and decaying.
Link can find an old wrench hidden somewhere around the Goron settlement. If he brings this to the Chief Smith in the Goron forge, he will recognize it as his favorite wrench, which he lost years ago. He thanks Link for bringing it to him, and says he sees Link is a pretty handy fella. Maybe Link, just maybe, is the person to fulfill the Chief Smith's dream- of restoring the wrestling arena. He'll give Link four or five bolts, and tell Link to patch up the failing supports.
The wrestling arena is actually suspended above a canyon. It is anchored in four or six places, on different levels. Link must use his agility to climb to the places where the supports are failing, and attach bolts. The last touch is tightening the chains that wind around the ring and serve as railings.
After fixing up the arena, some Gorons around town, including the Chief Smith, will notice, and mention that they miss the old Champion Wrestler, who moved out of town after losing his strength to the Violet Ore disease. Link explores the mountain, and following a winding trail, he finds the home of the old Champion (I'm just gonna call him Champ for now). He spends his time throwing small rocks (he can't lift heavy ones) at a nearby rock wasp hive that's been bothering him for a few weeks. He won't talk to Link, saying that he's too busy to talk to small fries.
The hive is inaccessible by foot, but Link can shoot a nearby bomb flower, which will explode and destroy the rock wasp hive. After this, Champ will talk to Link, with a small amount respect. Champ calls Link smart guy, commenting that maybe Link doesn't have brawn, but he does have brains. What? Go back to wrestling? Look smart guy, maybe you didn't hear, but all the Gorons are weak, weak, weak. We don't get the nutrients we need from mush soup. Anyway, the arena is falling apart. If Link has restored the arena by this point, Champ will think about it for a minute. "Well, maybe it would cheer my brothers up... Alright, I'll do it. But you've gotta fight me."
If Link agrees, the player will find himself in the arena, facing Champ. All the Gorons have gathered around to watch. All the buttons only make Link punch (which is probably just the sword animation without the blade), but he can still use agility moves. Champ is actually pretty fast, but not as fast as Link. He will block any punches Link throws at his front and counter. If Link stands still, Champ will punch at him. If Link can get behind Champ and hit his back three times, Champ will sit down and surrender. If Champ hits Link three times, Link will loose.
Whoever wins, Link and Champ stand facing each other outside the arena. Champ tells Link that was the best match he's had in many years, Link is pretty fast. All the others Gorons will cheer, saying that it was fantastic to see another match. Look, Champ is still fighting even though he's sick. Maybe we can all fight! We're all still champions!
Link goes to see Gor Indigneo again. He admits that he's heard everybody loved Link's fight with Champ. So is this what you do? You help others to serve your own ends? Well, I do know where the cog is. We left it deep in the Violet Mines before they were shut down. I'll send word for Gumbo, who has the keys to the minecarts, to let you go there.
In the dungeon, Link encounters Maple again. They find themselves together in the boss room when they're attacked. Working together, Link and Maple take the boss out. Afterwards, Maple swoops in to grab the cog, but then pauses. She realizes that before, she never would have had the courage to face that monster. She's grown a lot, even without getting any cogs. She doesn't immediately hand the cog over to Link, though. She gathers a vial of Venom from the boss, and using the cog's power, she synthesizes an antidote for the Goron's tooth rot disease. She gives it to Link, then goes back to Syrup to finish her witch training.
Link brings the antidote to the elder, who gives it to all the Gorons and cures them. The elder admits that maybe getting help from other people is a good thing, and the Gorons actually need it from time to time. He reminds Link to make sure he gets help when he needs it too.