Harry's use of Black Magic

[Bad Alias]

But he used modern(ish) language, modern(ish) accent, and a vernacular construction that originated in 1934.  So he is a relatively-recent arrival to the prison.

Unless you wish to posit that the prisoners can learn such things from an ambient gestalt or "overmind" of some sort...  But he spoke of a "stasis" (that Harry was disrupting) which doesn't sound like he would have been learning during that time.
 
I think this (mid/late 1930's (maybe 1940's (maybe post-WWII?))) is the last time there was a Warden, and this prisoner went in at that time.

He could have something like Toot when it comes to language; see Toot's explanation for where he learned to speak Russian in Changes.

Something I noticed last time I read Turn Coat was that when Shagnasty arrives on Demonreach, the island is apprehensive. Taking prisoners even on the island may be more difficult than some have theorized.

[noblehunter]

He could have something like Toot when it comes to language; see Toot's explanation for where he learned to speak Russian in Changes.

Something I noticed last time I read Turn Coat was that when Shagnasty arrives on Demonreach, the island is apprehensive. Taking prisoners even on the island may be more difficult than some have theorized.

Harry wasn't properly Warden then. There's commentary later (the beginning of Skin Game?) that he could take Mab down if she set foot on the island on he'd gotten up to speed on what the island could do.

[g33k]

He could have something like Toot when it comes to language; see Toot's explanation for where he learned to speak Russian in Changes.

That's a fair point.

I suppose the thing where he was "trying to recall" the phrase could merely have been a rhetorical flourish.

Everything about that figure is at the pretty-wild end of the WAG spectrum, just because we know so little about it... except that Harry is going to revisit that figure, one way or another.
 

[Bad Alias]

There's commentary later (the beginning of Skin Game?) that he could take Mab down if she set foot on the island on he'd gotten up to speed on what the island could do.

That's why it kind of surprised me.

[Mira]

Harry wasn't properly Warden then. There's commentary later (the beginning of Skin Game?) that he could take Mab down if she set foot on the island on he'd gotten up to speed on what the island could do.

 Actually it was at the end of Cold Days..   Page 502,  Molly just got the mantle and Mab is threatening  Harry with a gun, they were having a little debate about who is who's servant...
and Harry says;

"Demonreach," I said.  "If our guest pulls that trigger, take her below and keep her there."
The guardian spirit's vast shadow fell over us even though there was nothing actually casting it, and Mab's eyes widened.

So while Harry at that point might not know everything there was to know about the island or being it's warden, it is clear that on the island he had the authority to jail the Winter Queen if he so ordered.

[morriswalters]

Harry doesn't learn what he's Warden of until Cold Days.

[Bad Alias]

Actually it was at the end of Cold Days..   Page 502,  Molly just got the mantle and Mab is threatening  Harry with a gun, they were having a little debate about who is who's servant...
and Harry says;

So while Harry at that point might not know everything there was to know about the island or being it's warden, it is clear that on the island he had the authority to jail the Winter Queen if he so ordered.

It also comes up in Chapter Two of Skin Game. Harry asks what's to stop him from having Alfred imprison her. Mab responds "I am," shows Harry his blood on her finger, and states that the consequences to the mortal world would be "dire" if there would be no Mab and the consequences to Harry would worse if he tried it. She also stated that she was willing to throw down. Harry thought that the world needed Mab, and he was scared he might fail to take her down.

[Mira]

Harry doesn't learn what he's Warden of until Cold Days.

  Actually it is hinted at at the end of Ghost Story..  At any rate he tells Alfred to take Mab below and throw her in the slammer at the end of Cold Days if she shoots him and Alfred moves forward to comply.

It also comes up in Chapter Two of Skin Game. Harry asks what's to stop him from having Alfred imprison her. Mab responds "I am," shows Harry his blood on her finger, and states that the consequences to the mortal world would be "dire" if there would be no Mab and the consequences to Harry would worse if he tried it. She also stated that she was willing to throw down. Harry thought that the world needed Mab, and he was scared he might fail to take her down.

Harry simply thinks it through,  Mab is a bad guy, but our bad guy, as he puts it, putting her in the slammer would upset the balance and that might not be a good thing.  Then he does second guess himself a bit, no, by himself he might not be able, but on the island?  Yeah, I think he could do it.  It could have been a lawyerly bluff on Mab's part because she knows that Harry could do it while they were on the island.

[Bad Alias]

@Mira: I think he could take her, but I also think the cost to him would be worse than dire as Mab plainly stated. I don't think it's a fight he would "win" in any meaningful sense. It would be a Pyrrhic victory.

[Arjan]

@Mira: I think he could take her, but I also think the cost to him would be worse than dire as Mab plainly stated. I don't think it's a fight he would "win" in any meaningful sense. It would be a Pyrrhic victory.

Oh Molly would do fine and Lacuna would be a great winter lady.

[Mira]

Oh Molly would do fine and Lacuna would be a great winter lady.

  I think that thought crossed his mind...

[Arjan]

  I think that thought crossed his mind...

And Molly could make up with Carlos. I only see upsides

[Bad Alias]

Mab wouldn't be dead. She'd be imprisoned. Molly would still be the Lady, and Mab would still be the Queen.