With Zelda disappearance, morale feels quite low but now is not the time to search for the princess. Instead Impa and Link has to find the source of where all those monsters come from. It's recommended you start with Impa as her massive sword can cut enemies down with ease.
Central Fort secured[edit]
Even though you can take down enemy checkpoints, your first goal is to unblock the boulders with bombs near the center where the nearest fort is. If you're a thorough type, take down the south base where the ghost poe is. Go back to the center and remember to attack until the base boss appears. Attack the owner to confirm that you own this base. Then keep going to the top left to meet the general and Link as the middle north left is closed for the time being.
Protect the bombchus![edit]
With the path blocked, you have to go back and protect the bombchus in the south, marked by a circle and cross. Slow the enemies down by attacking generals, enemy checkpoints and bases that goes along the path the bombchu is going. Not to mention how big the bombchu looks like! Even if you fail, the Gorons will prepare more in this circumstances.
Sheik makes her appearance[edit]
There's a cutscene showing Impa, Link and the soldiers surrounded by monsters as Sheik with her harp shows up and astonishingly attack all the monsters. "Ocarina of Time" veterans would know who she is but it's best not to spoil at this time. Impa although skeptical, reluctantly agrees to ally herself with Sheik in the upcoming battle.
Conquering bases[edit]
After the cutscene, Wizzro will send reinforcements from the entrance where you and Link came from. Go back south and stop them from breaking through before going back around from the top base onwards.
You'll come across the Spirit of Cave which is closed for the moment. Go south of the passage to find the checkpoint officer, and two big poes. Attack them all to unlock the south east area. Clear two more checkpoint officers and conquer the Supply Base. At that point you need two bombs to get that boulder down. Also, get Sheik to take care of assault officers on the northern area of the map. Including the summoner that is north of the Spirit of Cave that has the treasure for Link.
Get Impa to the middle base and conquer that base to unlock it and let the bombchu reach its destination. That's when two bombchus will start moving. But there will be enemies in the way. They'll come out from south of the Supply Base. Including Wizzrobe that has been running behind the scenes. So take care of a few lizalfos and Wizzro that should be easy to deal with. Don't forget to blow the boulder where Wizzro's minions came out. Let the two bombchus blow the boulder in order to move on once the enemies has been cleared of dangers.
Impa, Link or Sheik should exit this level by going down to the base on the corner south-east. So go there to end this level.
In the cutscene, Impa hears the news from a soldier that someone in "Faron Woods" is a young girl warrior. Could it be Zelda? Continue on the next level.
Skulltulla location[edit]
After 1,000 kills, go to where you first bomb into the base and look somewhere on the right for the boulder. Blow it to find the skulltulla. The music should drop out and the sound goes up until you find it. The music will come back on after you attack it.