Although you're not technically at the Moonflow just yet, this is the road that leads to it, and the music is the same throughout. To start with just follow the road. You can speak with Shelinda although she doesn't have anything for you, but the path next to her leads to a chest containing 3 Lvl. 1 Key Spheres. There are some more new enemies you'll encounter along here:
- Ochus are the same as the mini-boss you fought in Kilika Woods, except now they're a lot easier to handle and have 7200 HP rather than 4696 HP. It has a normal attack that does about 350 damage and inflicts poison, and not much else. Lulu's Fira if you have it (Fire will do) will quickly put the hurt on, otherwise just physically attack it. It is susceptible to Sleep Attack with Wakka (if he has it) but it won't work all the time.
- Garms are wolves, so hit them with Tidus for a quick and easy kill. They occasionally inflict Silence.
- Bite Bugs are aerial, so hit them with Wakka's ball. However, unlike other aerial monsters they aren't magic-resistant, so one Blizzard or Blizzara will finish them off.
- Bunyips are slightly healthier versions of the Raldos you fought on Mi'ihen Highroad (and to a lesser extent, Djose Highroad and some parts of Mushroom Rock). One hit from Auron kills them, but maybe not one from Kimahri.
- Snow Flans are ice-element flans, so resistant to physical attack. One Fira kills them.
Further along here you'll find an X-Potion in a chest beyond Biran and Yenke, those troublemakers Kimahri seems to know. A chest further along still has 3 Level 1 Key Spheres (you're quickly racking up a lot of these). After another short walk you'll meet Belgemine again, whom you should talk to.
Fighting Belgemine's Ixion
This is a significantly easier battle than the Ifrit battle simply because it's 2 vs 1. That, and Ifrit is a bit more useful (at least now) than Valefor. Ixion's attacks don't hurt that much — ordinarily 250 or so and an Aerospark does about 300. After a while, it'll use Haste on itself, and you'll be instructed on how to give your aeons abilities they don't initially have outside of battle. This means it gets loads of turns, so watch out. About 4 or 5 physical attacks (doing about 700) followed by Hellfire will do Ixion in quite nicely with an overkill. After you beat it you'll be given the Summoners Soul and 2 Dragon Scales, and a tutorial on how to teach aeons new abilities. (If you lose, you get 6 Smoke Bombs rather than the Dragon Scales.) If you're wondering what the Dragon Scales are for, they will allow you to teach one aeon Watera. This is probably best used on Ixion to help combat Thunder-type enemies you'll be up against in the approaching Thunder Plains, but it's your choice.
Either way, continue down the road. Another tiny side path along here leads to a Magic Defense Sphere, which creates a Magic Defense +4 node on the Sphere Grid. In the next screen you'll actually reach the Moonflow. Once you regain control of Tidus, head along the shore to the next screen. You'll be introduced to shoopufs. Talk with your party members for a bit more info and a bit of back story, then head on through to the next screen. There are people here who will sell you supplies but they all overcharge for rubbish equipment you don't need. O'aka is present at the entrance — if you have to buy anything, buy it from him.
You'll meet Captain Lucil and the remaining Chocobo Knights here, then you can save. There's a chest behind Lulu in the tented area containing 5,000 Gil. Lastly, speak with Maechen to learn a bit more about the surroundings, then do as Wakka says and talk to the shoopuf handling guy in the previous screen to board the shoopuf. Once you're riding it, you'll learn a bit about why machina are forbidden. Then, the shoopuf will stop, and Yuna will be kidnapped by some Al Bhed…again. Tidus and Wakka will jump in the water to save her.
Boss Battle: Extractor
Tidus should first cast Haste on both Wakka and himself. If Wakka has an Overdrive make sure you stop the reels on Thunder to take advantage of the boss' weakness. The boss is immune to darkness, silence, and sleep so don't bother using their respective attacks. It will occasionally succumb to Delay Attack.
The boss has Aqua Shooter which does about 200 damage and has a weak delay effect on one person. "Readying Depth Charges" comes before Depth Charges, which you really don't want to see. The Extractor will float upwards in preparation, so to stop Depth Charges you need to deal enough damage (about 500) to make it come back down. Providing you don't ever let it do Depth Charges this battle should be pretty easy despite the fact that you only have two people — Haste will let you get lots of turns in anyway. If you are lucky enough to get a critical with Tidus and Wakka, you will get 2 Mega-Phoenix's.
Once you've got Yuna back, you'll be back on the shoopuf riding it to the other side. If Yuna being ambushed once wasn't bad enough, she'll be ambushed again on this side of the Moonflow by people asking if she's okay. Before you leave this area, don't forget to grab the Al Bhed Primer XII on the Shoopuf machina. Everyone else isn't going anywhere, so ignore what Auron says about guarding Yuna and leave the wharf. There's an Ether behind the left-hand Guado and next to the bench. Follow the red arrow to the shoreline, where you'll see a familiar face. It's Rikku! Can't say much about the undressing, but either way you've got a new party member! After her introduction to the rest of your party, you can carry on. However, there's a predetermined battle to go through first. Rikku's ability to steal should be familiar from the start of the game, although from now you start stealing more than just Grenades and Potions. You'll also be introduced to Mix, Rikku's Overdrive which creates some pretty wacky things if you're not careful. They generally will help you out although you must take care to use it when you need to because the resulting items can be potent healing ones that you could have benefited more from using it at another time. Generally, try to memorize what items combine to make what and use that combination again if you're desiring a specific effect. You can also check out a complete list of her mixes [here]. Otherwise, just add whatever you like together and see what happens!
After the battle there is a chest on the right-hand side that contains 4 Antidotes. Anyway, it will take some time to get used to Rikku. She doesn't have that much health so try to keep her in the fray for as little time as possible. Make sure you Steal with her as much as possible, as you can quickly accumulate a lot of useful items (Rikku's other initial command) that you can unleash on your enemies, combine with Mix or use to power up your aeons — Antarctic Winds you get from Snow Flans along this road will teach aeons the Blizzard-series of black magic spells. Just outside Guadosalam up ahead there's a chest containing a Mega-Potion. Head on inside.