I'm aware of those possibilities.
But that doesn't explain how Harry knows mechanics that afaik are Jim's creations i.e. how the Placard can be used. There is no tradition I am aware of that says the Placard can be used to create a super-threshold. So naturally, this is Jim's invention. Harry is aware of this but no other character apart from Mac seemed to be. But how would Harry have come by such information?
I have not once said that Christ didn't die for anyone's sins in either our universe or any other. That's not what this discussion is about. I questioned how that scene showed Sin as a quantifiable force and how the scene showed that Christ died for the sins of humanity in the Dresden Files. Because the scene in question doesn't show either of those things.
And for merely asking I have had my beliefs speculated on and been attacked personally. Which is inappropriate.
This discussion has gone off the rails. Clearly it's too much to ask to get everyone to answer the central question in the OP i.e. How does DRESDEN know how the Placard works and how to employ it when there is no in-text exposition or explanation and no real world common knowledge to support these apparent epiphanies? How does Harry even know about the concept of 'embodied intercession'? These are serious writing plot holes
He learned offscreen.
Personally, given Demonreach, I wasn't surprised. Demonreach is a prison. Not an armory, not a fortress, but a prison- specifically, a suspended animation-style prison.
For Alfred to hold the beings Alfred holds, Alfred needs to be able to counter their abilities. For Alfred to know their abilities, Alfred has to have some kind of scanning ability to assess new arrivals. Given Alfred has scanning abilities and exists to store things, I just assumed that the "armory" was one of the crystal cells, where the name placard reads "Cool stuff." So Alfred would have scanned them, like anything else, on the way in.
That was my assumption reading, Harry's got other paths to the knowledge.
