After journeying out to the city of Kvatch to talk with the Countess about the research her ancestor had done into the Ayleid, the party ventured north-east of the city to explore a new Ayleid ruin promising to possibly serve as the kind of forward base the Tsaesci might have been forming for larger-scale offenses against the Empire.
Within the ruin, the party found little in the way of a Tsaesci presence but did find a large cluster of Mushrooms and a Corrupted military force left behind. There was also a Daedric gate into an otherwise unknown realm of Oblivion. Here, they met, for the first time, with the Daedric presence known as Ithelia and her realm of Mirrormoor.