What did Snape know, and When did he know it?

[Mike]

No: HPFGUIDX 169367

> > Carol:
> 
> > Not necessarily. If Snape knows that Wormtail is the 
> > spy and that Peter Pettigrew is Wormtail, then he knows 
> > that Pettigrew is the spy.
> <snip>
>
> houyhnhnm:
> Snape knows Wormtail is the spy.
> 
> We have no evidence on which to establish the truth of the 
> major premise.  The fact that Snape recognized Wormtail as a 
> Marauder, if he did and I'm not convinced that he did, has 
> nothing to do with recognizing Wormtail as the spy.

Mike:
The Marauders made no secret of their nicknames. In SWM pensieve 
scene we hear them use all four of their nicknames, and they are out 
amongst their fellow students at this time. Sirius calls 
James "Prongs" while they are the center of attention in their 
picking on Snape and arguing with Lily. I would find it highly 
unlikely if Snape didn't know the nicknames of his boyhood 
tormenters, and which belonged to which. And I think there is instant 
recognition when the Map insults Snape. He calls for Lupin 
immediately, and I don't think it was for Lupin's DADA skills.

That said, I agree with houyhnhnm, I don't think it matters in the 
figuring out that Peter is Wormtail is the spy is the Potter's SK. 
What does matter is what Sirius said about the DEs in Azkaban.

> houyhnhnm:
> If Sirius' words can be taken at face value, and that's 
> a big if, then there were some Death Eaters who knew that 
> Peter Pettigrew was LV's spy within the Order.  <snip>

Mike:
Sirius' hatred of Wormtail and his resulting imprisonment because of 
being bested by Peter is what he used to keep his sanity in Azkaban. 
This is one area that he didn't need to and doesn't resort to 
hyperbole, imo. And, yes, we don't know who these unnamed DEs that 
screamed things out in their sleep were. But that's rather the point, 
isn't it? They are the generic any DE, as in, it seems any and all of 
them know that their Master's downfall came at the Potters and Peter 
sent LV there. So, maybe not all of them knew, but a fair few of them 
seemed to, imo. And I would have thought that Snape was one of them.

Now let's move on to Snape's treatment of Sirius in this affair.

> Carol:
> 
> > Snape clearly didn't know--could not have known--who 
> > the *Secret Keeper* was. Only the Potters, Sirius Black, 
> > and Wormtail knew about the Secret Keeper switch, so 
> > far as we know.
> 
> houyhnhnm:
> 
> "Sounds like they think the double-crosser 
> double-crossed them.  Voldemort went to the Potters 
> on your information . . . and Voldemort met his downfall 
> there."  I'm not sure how reliable is any information 
> that comes from Sirius, not because I think he is a liar, 
> but because he is careless of speech and given to 
> hyperbole, but if his words are an accurate representation 
> of what the Death Eaters were saying in Azkaban, it sounds 
> to me like they did know that Peter was the Secret Keeper, 
> and if some Death Eaters knew that, then Snape could have 
> known it, too, if he was 100 percent in the loop.
> 
> I don't think he was. <snip> Therefore he could not have known, 
> either that Peter was the spy or the Secret Keeper.

Mike:
As I said above, it doesn't sound like Snape needed to be anywhere 
near 100% in the loop, the knowledge that Peter led LV to the Potters 
seems to have become common knowledge amongst the DEs *after* the 
LV's downfall. Likewise, the knowledge that Sirius Black was *not* a 
fellow DE also seems to be common knowledge among the DEs. At least 
Sirius Black's cousins Bella and Narcissa would know this and, given 
that Snape and Lucius were thick as thieves, I would expect that 
Snape also knew this.

So, why didn't Snape tell this to Dumbledore? First let's look at 
Sirius' predicament. We get our initial information about Black's 
supposed DEness from the Daily Prophet and then Fudge. Fudge of 
course is the one who first told us about the Potter's Fidelius. But 
both these sources are highly suspect. I'm not sure that the rest of 
the WW held this same belief, if they thought about Sirius Black at 
all. And Fudge certainly seems to have a healthy self-aggrandizement 
streak in his story telling. So maybe only a few members of the 
Ministry (obviously including Barty Crouch Sr.) were interested in 
Black and they were the ones convinced of Sirius' allegience to LV. 
Rosemerta seems utterly surprised and still unbelieving in the Sirius 
turned on James Potter version.

Therefore, it seems that it was the Ministry that propegated the 
version of Sirius the DE. Did Dumbledore believe it? A better 
question might be: Why did Dumbledore testify that Black was the 
Potter's Secret Keeper? This same Dumbledore that seems to hold is 
own knowledge close to the vest, comes out and *testifies* to 
something that he truly has no direct knowledge?! He only knows what 
was told to him, he wasn't there at the spells performance. Why would 
Dumbledore give this testimony? 

It's just possible that Sirius Black had mucked up things once too 
often, and Albus Dumbledore had grown tired of bailing him out. From 
all indications, it seems heroic effort would be needed to get Sirius 
out of this one, the whole Ministry seemed to be convinced of Black's 
guilt. So maybe Dumbledore didn't want to fight for Sirius any more.

Furthermore, maybe Snape did tell Albus about Peter being the one who 
ratted out (pun intended) the Potters to LV. But it would have come a 
while after the Sirius-Peter confrontation in London, imo, because 
the "common knowledge" about Peter didn't become that immediately. I 
do believe that LV would have held Peter's identity close to the 
vest, only told a few insiders who the spy was. But after the 
downfall, those in the know would have released that information to 
both focus the other DEs anger at Peter and to exonerate themselves 
of any treachery. I assume that Voldemort would approve of this 
action, too.

So, Sirius is already in Azkaban by the time Dumbledore learns that 
Peter was the SK. But where would he learn that the Peter-Sirius 
confrontation didn't happen the way everybody believed it did? That 
is, Sirius blasted Peter to smithereens and blew up the street in the 
process. Now Dumbledore doesn't want his spy Severus compromised. So 
he doesn't come forward with this information that only could have 
come from another DE, because he still believes that Sirius is the 
murderer of 12 innocent Muggles, even if the 13th killing was a 
revenge killing.

The problem with this whole scenario; it doesn't answer why Snape 
would still believe that Black was the traitor of the Potters. Which 
comes back to my contention, Severus Snape was blinded by his hatred 
of Sirius Black. He either thought Sirius was part of the treachery, 
or more likely, he didn't care. He still thought that Sirius tried to 
kill him when they were kids and he wanted to see Sirius dead for his 
own self-serving reasons. 

> houyhnhnm:
> The fact that Snape knew Peter Pettigrew was Wormtail the 
> Marauder (or didn't know) has no relevance to his DDMness 
> or lack thereof, in my opinion.

Mike:
And I take this one step further. The (possible) fact that Snape knew 
that Sirius wasn't the traitor doesn't stop Snape from wanting Sirius 
dead. And Snape doesn't have to agree with *everything* that 
Dumbledore believes in, so it still doesn't affect his DDMness!!