Siedlisko zeugla, or nest, is the scene last "boss" battle. It takes place in a part of the kanały in the klasztorna which was previously inaccessible. The entrance to this area is found by going through the door immediately east of the dom kowala in the dzielnica nieludzi and then descending to the cellar.
The door is locked for the duration of the game. The key to unlock it is obtained only during the Epilog from a wounded Order soldier lying in the street, or from Triss