After several encounters with the trappy Summoner, he approaches you unusually with a request for aid. His Mistress seems to have gone mad and you may be the only help he can find.
1. You've answered Berwyn's, a half-lupine summoner you've had battles with before, plea for assistance. He came to you looking for help to deal with his mistress, a powerful mage. The half-breed mentioned some vague, dark plot she's up to at first, but on the way to her tower, he explained that she's apparently planning to take over some neighboring towns, as well as the fact that she's in possession of some kind of dangerous artifact.
Once you arrived at the Mistress's fortress, Berwyn opened the enchanted gate with a rune and led you inside. Now all you have to do is deal with the lady of this tower.
2. After exploring her tower, you did battle with Mistress Matiha alongside Berwyn. She was a powerful opponent, and you came face to face with the strange artifact your half-lupine ally mentioned: a runed stone that she seemed to be drawing power from. You were victorious against her, but after she was defeated, the Mistress teleported away along with that magic stone of hers. After a fast escape from the tower, her whole fortress teleported away as well, much to Berwyn's surprise.
Lady Matiha mentioned that this wouldn't be the last time you saw her, and Berwyn requested to join you in order for you to help each other for whenever she comes back, since it seems the half-breed doesn't know when she'll reappear. You accepted his offer, and now it seems you've gotten a new ally in the form of Berwyn, and his services and magical knowledge will be available to you if you need them.
Once you agree to help the fluff, he will take you toward his mistress' tower in hope of reasoning or, if push comes to shove, fighting her. Don't forget to play with the bookshelf before moving on towards the witch! A special reward (or another) awaits those who try to read. Past the bookshelf you may pilfer one more unique item, much to Berwyn's frustration. Finally, reaching the end of the tower, you shall find mistress Matiha, engrossed in her work. This doesn't last for long and, confronted with Berwyn's evidence, battle is inevitable. However, even in defeat she can still show her mastery of arts, vanishing with the crystal and soon the tower follows, leaving you to run for your lives.
Congratulations! You have a new trap companion (and 200 electrum coins)! Assuming you want him.