HBP post DH look Chapters 1-2.

[tommy_m_riddle]

No: HPFGUIDX 184314

> Carol:
> As Pippin said, he knew
> exactly how she felt. He had been in her position, begging Dumbledore
> to save Lily's life. How could he refuse to help Narcissa, even if it
> meant sacrificing his own life, under those terms?

Sarah:
I agree that he understood how she felt, but disagree with the second
part, because of the reason he *can* understand how Narcissa feels.
His real vow is to complete what he's set out to do on Lily's behalf,
not help all the mothers of the world who may bear some universal
similarity to Lily.  No matter how he might empathize with Narcissa,
*his* mission still is what it is.  If he fails to help Harry Potter
carry out what he's been set to do, he fails at life, basically.  If
he's dead, he probably can't finish his mission.  (I know Dumbledore
still did, kind of, but Snape would have died in much worse standing
had he died of some Unbreakable Vow with the Malfoys, or been taken
out as a consequence of killing Dumbledore.)

If Snape thought for a second that he might actually die from any of
this, he not only could refuse, he *must* refuse, to preserve his real
interest.  But that's not an issue for him.  He reckons everyone
involved expects Draco to fail, and Snape to be the one to kill
Dumbledore, so the Vow won't kill Snape.  And even if Draco actually
does manage to pull it off, Snape hasn't broken the Vow, just his
promise to Dumbledore.  I think Snape is pretty confident that he
won't get taken out by someone like Harry Potter as a side effect of
killing Dumbledore, with good reason (see: their duel afterwards).

He makes the Vow because it's promising the exact same thing to two
different parties.  There's no additional danger involved on his part
by making it.  It's a win-win situation.  Unless he died, then
everyone involved would have some pretty bad repercussions.  But Snape
is confident that won't happen, so no worries. 

Carol:
> But, still, if he hadn't already promised DD that he would kill him, I
> don't think he would have taken such a dangerous step, placing his
> life on the line and possibly pledging himself to do the unthinkable.

Sarah:
Of course not.  He wouldn't even have killed Dumbledore in the first
place if Dumbledore wasn't dying already.  But these plans were all
made after Snape (and only Snape and Dumbledore) knew that Dumbledore
had a year, tops, to live.  If he'd been approached to kill Dumbledore
when Dumbledore was healthy, he could have just said, "Please, he's so
much more useful alive, where I can spy on him."