I’ve been thinking about the Dark Hallow. The Dark Hallow doesn’t flatly kill people by itself; rather, its aftereffect creates a vacuum in which life energy is naturally ripped away from anything nearby in order to fill the void. Dresden explains to Butters exactly what the energy consumed is, and that the loss of life doesn’t happen immediately during the spell, but afterwards to fill the magical void. So, theoretically, it could be possible to do it without causing loss of life. And if it’s as simple as that, it’s actually a pretty stupid idea to do it in such a densely packed area as Chicago, where any number of things can interrupt the very delicate spell.
However, I don’t think it’s as simple as that. Bob tells Harry in Cold Days that probably only Cowl knew that the rite had to have been performed on Halloween, so it’s not likely that Grevaine chose Kendall College as the site of the rite just because he was antsy to get it done. Rather, it’s because there’s a huge amount of energy required to get the spell going, and heavily-populated Chicago is probably necessary to get that energy moving. Most of Dead Beat is spent with Harry chasing the actions of the Kemmlerites ‘priming the pump’ – tracking the necromantic killings in Chicago, summoning the hunter spirits from the Kahokian artifacts at the museum, and experiencing Chicago descend into chaos with the blackout.
When preparing Sue for her epic ride, Dresden tells Butters that the spell requires a massive amount of “dark power” to absorb. He lists four sources that the Kemmlerites are using for absorption – their own necromantic energy animating corpses, the warrior spirits summoned with the Erlking, the growing fear and tension from all of the mortals in Chicago, and the turbulence from the last several years. All of this creates enough energy to start the vortex and be absorbed. The vacuum effect would strip all life for a mile in all directions.
If Dresden travelled out to, say, Wyoming or Montana, to do the rite, I don’t think he could get the same amount of free energy. There’s no mortals to terrify, few dead spirits, and no recent turbulent activity. A remote island is actually worse, as it’s surrounded by water and thus only has its own bubble of magical energy. I think there’s only two places he could do it – Chichen Itza during the mass slaughter, and Demonreach. Chichen Itza wouldn’t be used for two reasons, being (a) the Red Court could easily have bumped Dresden’s shoulder when noticing a giant vortex coming down close to them, and (b) Maggie would have likely been killed from the aftermath.
Dresden knows that the island is dark, and knows that it’s a node and likely has the amount of power he needs – but at this point in the story, he doesn’t know what the island is. I could see him having the Scooby Gang take him out there, telling them to sail a few miles out, and performing the rite. It would seem like the least problematic option. But by absorbing even part of the essence of what is trapped down there… Dresden would, for certain, be Changed.
By the way, rereading the section of Dead Beat reminded me that there’s one other similarity that Cowl has to Dresden: at the final battle under the vortex, Cowl hits Dresden with a force punch that knocks him down, a spell which Dresden was surprised that he didn’t feel a gathering of energy for. Later in the books, Harry creates force rings which hold kinetic energy and release force punches without gathering energy. Dresden is the only one who we’ve ever seen use a talisman in this way. Slightly suspicious.
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