Inside the world dominated by Hermaeus Mora, you will first of all have to get used to the untypical structure of the levels. Everything is prone to change here and the whole area is in fact a large labyrinth. Its first part is by far the most complicated - approach the organic button (scyre) in the middle of the platform on which you're standing and use it. Enter the moving corridor and cross it to the other side (the one of the right).
On the next island, search for another button, use it and head back to the corridor (however instead of crossing it, stand in one place and let the tunnel turn). In the middle of the location, a bridge leading to the shining book will be created. Head there and use the mysterious book (that way you will reach Chapter II).
After reaching a tunnel with moving grates, cross is to the other side and turn the lever. Get ready for a hard fight - you will have to face two Seekers and a Lurker. It's best to eliminate the two first in the first place and leave the enormous beast for later (projectiles fired by the Seekers can be very dangerous). After getting rid of them all, use the next button and cross the newly opened gate. Behind it you will see a book-gate to Chapter III.
In the next room you will have an unpleasant meeting with two Seekers - you won't be able to avoid confronting them. The beasts are rather fast and capable of shooting deadly magic projectiles - try not to fall into the water during the fight (it will end very baldy). After dealing with the tentacle creatures, go up the stairs to the upper level. There you will come across yet another moving tunnel - in order to leave the location as fast as possible, cross it. If you however want to collect some treasures, you can always check out the local islands (look out for monsters!).
In the corridor you will come across two Seekers - you should already know how to fight them. Go through the gate (activated with the organic button) and head to the end of the tunnel. When you reach the exit, the whole construction will turn around and you will have to fight a Lurker. Defeat him and head past the corpse to the next tunnel. It will turn yet again. You will end up in a location with a organic button - use it and cross the few consecutive, linear locations.
The further part of the level consists of straight corridors, ponds with tentacles and a couple Seekers. By the end of the path you will come across a book leading to Chapter IV. Use the lever and approach the book standing in the middle of the strange "hill". It's the Epistolary Arumen. Use it and Hermaeus Mora will appear.
Regardless of your choices during the conversation with the Daedric god, you will learn the second Word of Power of the Bend Will Shout. You will also have no choice regarding the price you have to pay for it - one way or another, you will have to return to the Skaal Village and unveil the secret of the villagers to the monster. Before heading there however, choose one of three powers offered by Hermaeus Mora:
- Dragonborn Force - the Unrelenting Force Shout deals more damage and can disintegrate enemies;
- Dragonborn Flame - if you kill an enemy using the Fire Breath Shout, a friendly Fire Wyrm will be summoned from its corpse and will fight for you for 60 second;
- Dragonborn Frost - the Frost Breath Shout encases enemies in ice.
Choose one of them, use the book once again and you will be moved back to Nchardaku.