Step 5: Reach the Magister's chamber
There will be now a short cut-scene - a conversation with Fenris #1, where you can ask him about Magister. Note that elf has joined your party. What's more, he'll be its mandatory member for this quest. Be sure to take at least one mage for this mission. Also increase resistance of your party members against injuries connected with fire element and that's because the greatest threat inside the manor are rage demons. Once you're inside the [Hightown - Danarius's Manor] location (M18, 2), go to the only door there #2. Ignore all closed passages on your way, because you can't enter most of them unfortunately.
There is a first group of shades #1 (M18, 3) in the next room. Fortunately you can kill them easily, but you have to be careful because there are plenty of them. I suggest fighting them in the first room because there is a fire trap difficult to disarm at the entrance to the second room. Other monsters are located in the north-central room of the mansion #2 (M18, 4).
You have to be very careful, because there will be few rage demons in the group of monsters attacking you #1. These monsters are not only tougher than shades, but also can inflict substantial based on fire element #2.
It is good to fight shades and rage demons in one of the previously explored rooms, so not all of the nearby monsters will join the battle. After winning the fight go to the main manor's room and deal with the group of shades near the stairs #1. Magister's chamber is located to the east from this place, but you can't go there right away because you need a key. So select the only door leading to the northern part of the manor #2 (M18, 5).
Once you get to the new room start with disarming or bypassing a standard trap #1. Exploring a room to the north is optional. You will be attacked by shades there and you'll find a chest. In order to reach a monster that possesses a key, you need to go east #2.
A second northern room is worth of being explored. It is not guarded by any monsters #1 and you can find two chests there. At the end, go to the eastern room (M18, 6). You have to eliminate new shades and rage demons there #2. As before it is good to get rid of weaker shades first and leave more powerful creatures for later.
After killing all monsters examine the remains of one of the rage demons and you should notice that he has Magister's key #1 among others. Take the opportunity and open the nearby chest and return to the manor's central room. Use the stairs and go up #2. If you want you can explore the two nearby smaller rooms. In the northern room you'll find a locked trunk and in the southern room you'll find a chest.
Step 6: Defeat an Arcane Horror
You can now use the newly obtained Magister's key to open the eastern door leading to the Danarius's chamber #1 (M18, 7). Unfortunately you won't find a man wanted by Fenris there. Instead of that you have to fight shades, rage demons and a mini-boss - an arcane horror #2.
I suggest eliminating shades #1 first. As previously mentioned they are not too strong, so they should die quickly. After dealing with all shades (or at least with majority of them), start attacking an arcane horror #2 and that's because this monster is able to cast very powerful spells. At the end get rid of the rage demons.
These fights can be carried out in two main locations. One possibility is to retreat to the manor's central chamber #1. You can also fight in the Magister's chamber or at the door leading to it. The second alternative is particularly interesting when fighting an arcane horror #2 while it can block the way and other monsters can't attack you.
Defeating all monsters will be awarded with a short cut-scene involving Fenris, who is very disappointed with the absence of Magister in the manor. Take a moment and examine monsters' bodies #1 and open three different chests #2.
Step 7: Leave the manor
Take the same path to the exit from the manor #1 (M18, 2). Once you're outside the manor (M4, 5) the game will automatically launch yet another cut-scene and conversation with Fenris. You can talk with him about Danarius and also flirt with him. This conversation will end with decision whether to invite him for further adventures with your party #2 or to thank him for cooperation. If you choose the first option, a new quest connected with Fenris will be activated. Additional dialog options will be available if you have any mage (e.g. Bethany) in your actual party, because elf has clearly negative attitude against this class. In this situation you can act in few ways, but generally when you stand up for mages it will improve your relationships with them but worsen it with Fenris. On the other hand, standing up for Fenris has an opposite result. If you do not want unnecessary conflicts, please choose neutral answers or remove all mages from your active party before leaving the manor.
Unlocked companion quest: Fenris Recruited