What we know; 1. Sandra Marling has been working on this horror con for a year.
2. Madrigal, aka Darby Crane, was booked for a year to appear at the horror con. 3. Madrigal is a member of that sub branch of WCV who get off on fear, can't remember their nsmes, 3. The fetches appear and produce all kinds of fear, that had to have been some kind of psychic buffett.
I can't help but think that Sandra was central to all if this, and who was she working for? Madrigal was set up to take the fall, but for what and for who? It had to to have had something to do with the attack on AT.
We know that Madrigal was working for Cowl. Could Sandra be Kumori?
Who could have known a year ago that Molly was going to develop powers?
I feel that Molly was not central to this at all. This was set up for another purpose and she and Harry messed it up in grand style. Someone is really pissed their plans went down the drain. Cowl, maybe.
Of course, now that Molly has developed these powers, it's just perfect that Harry is there to take her on as an apprentice. And, she has definitely attracted the notice of Mab.