"Sir Roderick -- the man who had this house built, actually -- made an unfortunately worded deal that started the whole trouble. He contracted a fae to help him get a child... and then to protect the children of Geap Manor."

So a minor had protection within these walls, and they were somewhat of a sanctuary anyway, with how Unthank had tied himself to the house. But an adult was in danger. Not as much here, no, but enough. There was a curse out in the world working against them. So, further deals were always necessary.