Go find Yuna and talk to her. In the morning return to the campsite and locate the Lucid Ring. Then head east and follow the road to its end at reach the Calm Lands.

Follow the ridge down to the west until you reach the plains. In the middle of the plains is a trading post and just behind it is a chest with a Lv. 2 Key Sphere. In the southeast corner are 2 chests with 5000 gil and 10000 gil inside them. In the northwest corner you'll find the Al Bhed Primer XXIII. On the east side you'll find the Monster Arena. You can reach the Remiem Temple in the southeast corner.

When done exploring, go to the exit at the northeast corner. When you cross the bridge, you'll be forced to fight Defender X.

You can go down into the valley using the path on the right side. At the bottom, you'll find the entrance to the Cavern of the Stolen Fayth. Along the path to the right you can pick up the Rusty Sword.

This section is optional for the overall story but if you want to obtain all the aeons, you'll have to complete it. Continue along the path into the cave until you come to a short side corridor on the right, at the end of which is a Megalixir.

After passing through a larger chamber you'll come to a fork. Take the right path to reach a small chamber with a Lv. 2 Key Sphere. At the next fork, take the forward path to reach a Fortune Sphere. Take the path to the left and at the crossroads, pick up the 2 Mega-Potions there. The left corridor has the Al Bhed Primer XXV.

When you approach the next large chamber you'll have to battle Yojimbo. After the battle, you can use the teleport pad. The chamber on the left contains a Flexible Arm. The chamber on the right contains an MP Sphere and 2 X-Potions.

Use the transporter to enter the Chamber of the Fayth where you'll need to bargain for the price to obtain the aeon. If you offer the fayth anything less than half his asking price, he'll dismiss you. If you offer him at least 3 times his asking price, then in addition to gaining Yojimbo, you'll also receieve 2 Teleport Spheres. When you are done, you can use the transporter to return to the cave's entrance.

After you pass through the gate, Kimahri will have to battle Biran Ronso and Yenke Ronso alone.

When you reach the first section, check the ledge on the far right to find a chest with 20000 gil. A short ways forward on the left side is a hidden chest with 2 Mega-Potions. Continue along the winding path until you come to a fork with a short path uphill where you'll find Braska's Sphere. Going on, you'll come to another fork with another short path uphill. At the top you'll find a chest with a Defending Bracer. When you come to the next fork, take the right one and find 2 chests hidden under the main path to get an HP Sphere and a Lv. 4 Key Sphere.

When you reach the end of the path, you'll have to battle Seymour Flux and Mortiorchis.

After the battle, head north until Tidus finds himself back in old Zanarkand. Go in the door in the upper right to meet the fayth from the beginning. When it disappears, go outside and talk to it and shortly you'll wake up. Follow the path until you come to the cave.

When you reach the fork, you're forced to take the left path as the forward one is blocked. At the water, Tidus, Wakka, and Rikku will swim to the other side. Once there, you'll have to do the first trial which involves Wakka hitting the center of a target blocked by a rotating shield. After completing the trial, get the Lv. 1 Key Sphere from the chest that appears in front of you.

Return to the first fork. The forward path will now be open. You'll come to another fork. Take the right path to reach another underwater area. At the end of this path, you'll have to do the second trial - send Rikku to the Green, send Tidus to the Blue, and send Wakka to the Red. Afterward, get the Fortune Sphere from the chest that appears.

Return to the previous fork and take the right path. After a short underwater passage, you'll find 2 chests with a Return Sphere and a Recovery Ring.

Go back to the first fork again and take the left path once more. This time on the right side, you'll be able to enter the alcove and get the Pep Talk there.

Return to the second fork and go left. On the left side there will be a series of step-like rocks now that will take you upwards. Just as you reach the end of the cave, you'll be attacked by the Sanctuary Keeper.

Follow the path around the mountain. At the bottom of the mountain trail, you'll camp out for the night. When you are ready, head north into the ruins.

In the first section, look for a chest with a Fortune Sphere on the left. Then next part you'll find a Spiritual Targe in a chest on the left.

Once you reach the dome, head down until you are in a partially covered section. At one of the corners, you are able to climb up to the top and backtrack to find a chest with 10000 gil. When you reach the center, there is a dead-end on the right with a Friend Sphere. Continue on and just before entering the next section, look for a ramp downwards that will lead you to a Lv. 3 Key Sphere.

When you enter the next section, you can get a Luck Sphere on the right just before the stairs. Go up the stairs to reach the Cloister of Trials.

1. In the first chamber, examine the map and then step on the corresponding tiles to match up with the display.
2. 6 pedestals will appear and the door to the second chamber will open.
3. Push in the outer pedestals on both sides to activate the 4 different puzzles in the second chamber.
4. Examine the map in the second chamber and then step on the corresponding tiles just as in the first chamber.
5. After solving the 4 puzzles, take the Kilika Sphere from the left side of the map in the second chamber and place it in the left pedestal in the first chamber.
6. Take the Besaid Sphere from the right side of the map in the second chamber and place it in the right pedestal in the first chamber.
7. When you enter the second chamber this time, you'll fight the Spectral Keeper.
8. You must return to the Trials later to find the hidden treasure.
9. To get the Destruction Sphere, solve the final puzzle which involves finding all square blocks in both chambers.
10. Once you have the Destruction Sphere, place it in the slot on the right of the map in the second chamber to reveal the treasure which is a Magistral Rod.

Continue on past the Chamber of the Fayth. After reaching the Great Hall, go forward to start your battle with Yunalesca. Once the battle is over, search for the Sun Crest at the top left and then leave. Once you exit the dome, the airship will pick you up.

Head to the upper deck and talk with Kimahri and Yuna. Go back to the bridge then talk to Cid and select Highbridge from the list.

Go forward to meet with Maester Mika and then the Fayth. Afterward, you'll tell Shelinda about your plan and return to the airship.

Talk to Cid again and you'll have a new option in the list called "Sin". After selecting it, head to the upper deck of the airship. Once outside, you'll have to fight Left Fin then Right Fin. Immediately after that you'll have to fight Sinspawn Genais and Sin (Core).

When you are back in the airship, head back to the outer deck and talk to Yuna. Then when you're ready return to the outer deck to take on Sin.

After leaving the airship, you'll enter a very large maze of pathways called the Sea of Sorrow. There are 5 chests to find in the maze. There are 3 on the left containing an Elixir, a Phantom Ring, and Special Sphere. There are 2 in the upper right containing a Wizard Lance and a Lv. 3 Key Sphere. At the far north there is a staircase leading up. At the top of the stairs, you'll have to fight Seymour Omnis.

Afterward, you'll find yourself in the next section: City of Dying Dreams. The first glyph you'll come to wants you to kill 10 fiends. After killing 10 enemies, return to the glyph and touch it to reveal another. You must kill 10 more to open the next door and then 15 to open the final one. After you have opened all 3 doors you'll find a chest with a Lv. 4 Key Sphere.

Continue forward along the path until you see a blue tile creating a brige. Stand on the tile and press [X] to make it rise so that you can reach the Four-on-One. A short ways further, you'll come to another tile. Stand on the tile and press [X] to reveal a chest with a Defending Bracer.

When you come to a larger open area check the west wall for a glyph that when touched, opens a section of the wall to reveal a chest with a Megalixir in it.

In the middle of the large open area is a ramp leading down to a chest with 20000 gil gil in it. Step on the blue tile to make it rise so you can reach a high ledge with an HP Sphere and Defense Sphere. Step on the other blue tile to get back down.

Further on, there's a small alcove on the right with a doorway behind the pillar. If you go in, you'll slide down to a lower level where you'll find a Laevatein. Climb back up the ledges to get out. At the top, you'll find yourself at a crossroads. Go north and touch the glyph on the tower to reach the next section.

You'll find yourself in a circular area. Run around and try to grab the small egg-like crystals that appear while avoiding the spike crystals popping out of the ground. If you touch a spike crystal, you'll be forced into a battle. The egg crystals disappear after a short time, so grab them quickly when they appear. Each one will give you an item: Stillblade, Prism Ball, Skill Sphere, Knight Lance, Mage's Staff, Infinity, Wht Magic Sphere, Attribute Sphere, Wicked Cait Sith, Hrunting.

After you have picked up all ten, you'll be transported to a place that looks like old Zanarkand and finally meet up with Jecht. After you talk with him, you'll have to battle Braska's Final Aeon. Once you defeat it, you must summon and then defeat all of your own aeons. Then, you'll enter your final battle against Yu Yevon. Enjoy the ending!