The Mire-Maiden was what has become of the Fair Maiden after the Collision. She emerged from the ruins neither exactly fair nor exactly a maiden (nor particularly sane). Her sense of beauty got twisted, her desire for perfection got obsessive, violent, and her pleasures got even more bizarre. Promptly after her birth, she went on a rage-driven rampage, killing or corrupting everything in her way. She found FNORD, an Hour weakened by the Collision, and devoured them.
The Mire-Maiden lashed out at everything, driven by insatiable desire to reshape things in her twisted image. This is how she found another Hour born of the Collision, The Stone Meridian. Unfortunately for her, The Stone Meridian was one of the few things in the world not affected by the event in a negative way. A grueling battle ensued between two young Hours, shaped by the strife, for the right to exist. In the end, The Moving City obliterated what remained of the Fair Maiden, and sent it Nowhere. But not before allowing a part of it to live on as one of its Names, reshaping it as The Minister in Black.