After reading Blood Beast, I think there's an even greater possibility that the theory about Nadia and Juni is true. Spoilers in white.
So, Juni comes back to Carcery Vale, right after the incident in the cave. Just a coincidence that Misery fell ill? I think not. She worms herself into Dervish and Grubbs's lives, and she tells them she's been practicing magic for the last year. Again, I think not. You don't get that good at it so soon. She helps Grubbs escape, then on the plane, it's revealed she's on Lord Loss's side.
Am I the only one thinking they're trying to open up the tunnel between the two worlds in the cave were Bec died?