Er...Is it a coincidence that the last time a skinwalker was mentioned confronting a warden, that warden was Morgan, who got rid of it at a nuclear test site, which might have occurred sometime during WW2, when such things were being done, and that it was during WW2 that Kemmler was last killed? Idk. This whole apprentice of his (Kemmler), and the skull with that knowledge Bob, plus this last book apparently reinforcing a bunch of old stuff, maybe pulling it together, plus stuff the author has said out of the books (now being mentioned in some way in Ghost Story), sort of seem to be setting something up. Too much Kemmler, Black Council, and supernatural entities, plus whatever reason the Winter Queen is in dire need of help such as a Winter Knight could provide of late/her resources seem to be stressed + all that attack on Arctis Tor stuff, etc.....
*Before Dresden, I mean.