HBP post DH look Chapters 1-2.

[pippin_999]

No: HPFGUIDX 184292

 
> Alla:
> 
> Oh LOL, now that is a major DUH moment indeed. Unless of course 
> Dumbledore had other spies which we never knew about, hehe. I kept 
> thinking that those Spies mentioned by Fudge will appear, but since 
> they are not, sure, for Dumbledore to know Snape had to learn from 
> Voldemort.

Pippin:
Oh, we got loads of other spies. Arthur and Kingsley spying on the
Ministry, Lupin spying on werewolves, Mrs. Figg spying on Little
Whinging, Mundungus and Aberforth spying on the WW's underworld, and
so on. But Snape seems to have been the only one who had Voldemort's
confidence.


> Leah:
> > Why did Snape take the vow?  <snip excellent reasons>   Could be
any or all of these.
> > 

Pippin:
It puts Snape into the same position as Dumbledore when Snape begged
him to save Lily, reinforced by the water imagery. Just like Snape
before her, Narcissa does not realize that she would be helped in any
case.

I think we are meant to look to Dumbledore for a clue to Snape's
feelings: pity for Narcissa, mingled with disgust at her lack of
concern for other innocent lives.

Pippin