Note that this is the second visit to Mount Corel. If you are on Disc 1 and have not visited North Corel and Mount Corel before you should check out the strategy guide section for Mount Corel section on Disc 1.
Take your newly formed party lead by Cid to North Corel using the map below for reference:
Save your game before you enter North Corel as there is an upcoming portion of the game that is timed which you may need to make more than one attempt at. Travel out the northern exit shown in the screenshot below.
Continue down the bridge and follow the train tracks all the way back until you reach the Mount Corel Reactor pictured in the second screenshot below.
Approach the center of the reactor and you will be thrown into battle against two Shinra Soldiers (Attack Squads) which are fairly easy to defeat. A timer will finish as soon as you complete this fight so it is recommended that you read ahead so that you are fully aware of what is coming before proceeding.
There will be a few lines of dialogue before a train comes rushing through carrying the Huge Materia towards the town of North Corel. Cid will commandeer another train and use it to catch up to the first train.
From this point onward you will be subjected to a 10:00 minute timer that does not stop when you go into the menu screen so you have to be as quick as possible.
In order to have Cid catch up to the other train you have to alternate between pressing 
(Up) Button on the directional pad and the 
Button. The team will jump onto the train with the Huge Materia once you catch up to it.
There are 5 scripted fights that you must now complete, one on each train car. The fights will start automatically as you walk across each train car.
Gas Ducter
This is a standard fight and regular physical attacks will will get you through it.
Gas Ducter (x2)
This is another standard fight but consider using more powerful attacks such as Aqualung, Trine or Magic Breath from your 
Enemy Skill Materia.
Wolfmeister
This enemy has 10,000 HP making it a little bit more difficult of a fight, but not because it increases the risk of your character’s being KO’d, just because the time it takes to bring Wolfmeister down will eat away at the 10:00 timer.
Eagle Gun
Make sure that you take the time to steal a 
Warrior Bangle from Eagle Gun using your Steal Materia.
Use your most powerful attacks, such as Enemy Skill Materia or 
Comet Materia, as it has 17,000 HP.
Shinra Soldier (Attack Squad)
One last standard fight against a soldier.
Following these five battles you will have to stop the train. You have to either push them both up at the same time or both down at the same time. Use either: (Up) Button + Button or 
(Down) Button + 
Button.
The train will speed up each time but if you manage to do this three times the train will come to a complete stop as it approaches North Corel.
Your reward for successful completion of this event is the Huge Materia and the townspeople will reward you with an Ultima Materia which is one of the most powerful spells in the game.
Note that you do not have to complete this event successfully in order to complete the game. You will not receive the Huge Materia and would have to purchase the Ultima Materia from one of the townspeople.
Bahamutype-0
In order to obtain the 
Bahamut ZERO Materia later on in the game, which will reward you with the Bahamutype-0 Trophy as well, you need to obtain a number of items including each of the four Huge Materia with this one being the first of the four.
You may want to consider restarting your game if you are unsuccessful in stopping the train headed towards North Corel as there is no way to obtain this trophy unless you retrieve this Huge Materia.
Note: If you manage to acquire all four Huge Materia you will be able to obtain Bahamut ZERO Materia later on in the game.
The team will get a free rest at the Inn before they leave, but before you leave North Corel, enter the house on the far left side of the screen.
Speak to the woman in the black jacket and blue pants to receive 
Catastrophe, Barret’s Level 4 Limit Break.
Loose Cannon
You will receive the Loose Cannon Trophy once you teach Barret his Level 4 Limit Break, Catastrophe, using the Catastrophe item listed above. Check out the Learning New Limit Breaks section for more information on how to teach your characters their strongest Limit Breaks.
You only get one clue where to head next and that’s if you board the Highwind and press the Button to return to the main deck. Cid will ask “Shall we head for Fort Condor?”
On to the next mission!
