In this chapter, you wake up in a cage that the guard frees you from. He is your only companion now. In this location, there are some new opponents and some of them are dark ones. This means that they are vulnerable to your Light attacks. This place is full of pitfalls and you have to watch out for the traps. Remember that you are left with two companions only. If You fly into a trap, you will lose some of your HP.
After you fly to the very bottom of the location, you will find a door. Cross it to find your companions locked up. To free them, use the lever below.
After you free your companions, you will have to solve a puzzle to proceed on. The mechanism in the dungeon stands in your way. To move on, you have to pull the lever (marked in blue) to the right, and move the right part of the mechanism (red circle) with Igniculus. As soon as it moves up, light up the symbol in the upper part of the machine, using Igniculus. This part will move towards the rest of the machine and open the passage. Parts of the machine that you have reset have been presented in the screenshot. After you have flown down to the very bottom, you will find a door. There, you will receive a quest from Oengus and you will enter a labyrinth with him.
Oengus will task you with crossing a labyrinth to complete this chapter. First, fly down to the very bottom and cross the first door. In the shelters next to the door, you will find chests or opponents. After you get into the next part of the labyrinth, cross the door down below. Then, the one on the left. In the next part, cross the upper door first, and then the lower one. If you confuse the order, you will return to the starting point.
In the room that you enter, there is a captain and several warriors. Your companion will acquaint you with them and he will be waiting for you by the door, afterwards. After you talk to him, you will end his quest. Then, leave the building. On the right, you will find Cordelia, who turns into a huge dragon and is the first one, of the last five bosses you are going to fight.
After you kill the boss, you will grab the moon and grow. This way, you will obtain an achievement - Over the Moon. Also, you are rewarded with an opportunity to unlock an extra skill in each one of your party members. To end this chapter, reach the end of the platform and walk into the next location.