If Snape told DD about the UV, how would DD have responded?

[justcarol67]

No: HPFGUIDX 137563

First, let me state what I think happened in "Spinner's End," a
chapter that is very much open to interpretation. I think that Snape
did not anticipate the Black sisters' visit, that LV had not told him
the plan to kill Dumbledore (if LV trusts Snape, why have Wormtail
spying on him?), and that at first he is bluffing. His first goal is
to allay Bellatrix's suspicions by telling her essentially what he
told Voldemort, with some lies relating to Sirius Black and Emmeline
Vance thrown in for good measure once he has determined that Bellatirx
is not in a position to verify his story.

Then he turns to Narcissa, still bluffing at first but then using
Legilimency on her to find out Draco's mission. At this point he turns
to the window, away from the women, to regain his self-control. When
Narcissa asks him to help and protect Draco. This, naturally, is what
he already intends to do. Draco is a student in his House and the son
of his friend. Even when Narcissa asks him to take an Unbreakable Vow
to help and protect Draco, Snape is not really worried. He can't say
no, of course, without betraying his loyalty to Dumbledore and being
murdered by two angry women, but saying yes is only swearing to do
what he already intends to do ("help" being subject to interpretation
and not necessarily meaning what Narcissa intends it to mean). It
seems unlikely that he will be placed in a position where he'll be
forced to break the vow. If it's a choice between saving Draco and
dying, he will of course save Draco.

It's only when Narcissa throws in the unanticipated third provision,
to finish the task for Draco if Draco fails, that Snape sees his
danger and his dilemma. If I'm right and he used Legilimency on
Narcissa, he knows at this point that it could come down to his life
or Dumbledore's. His only hope is that Draco's cowardice and
incompetence will prevent him from getting anywhere near Dumbledore.
We know from his interview with Draco that he doesn't know the plan
about getting Death Eaters into the school. He knows only what
Narcissa knows--that Draco is somehow supposed to kill Dumbledore.

Now comes the part where we know next to nothing. We don't know
whether he told Dumbledore about the Unbreakable Vow (I think he did,
given DD's lack of surprise when Harry tells him about the overheard
conversation). It's possible that he only told him about the first two
provisions. Even so, DD knows that Draco is trying to kill him and if
he also knows about the Unbreakable Vow, he must know that if the
protections on the school fail and Draco succeeds in getting Death
Eaters into the school (the only way he would dare to confront DD),
Snape may be faced with a terrible choice: die fighting on DD's side
or protect and "help" Draco. If "help" Draco means kill Dumbledore,
then the choice will be between letting Draco die and dying himself or
killing Dumbledore. I think both DD and Snape trust in the protections
that DD has placed in the school and neither thinks that matters will
reach this point. And yet the vow is dangerous, and in combination
with the curse on the DADA position, both DD and Snape must feel a
sense of entrapment and impending doom.

Sorry. More than I wanted to say on this point. The question I wanted
to pose is this: 

[Suppose that Snape is in fact loyal to Dumbledore, that he realizes
he has been trapped by a combination of Voldemort's malice and his own
pride and folly (agreeing to take the vow and thinking he can slither
out of it through cleverness; not anticipating the terrible third clause.)

Suppose that he goes to Dumbledore and says something like,
"Headmaster, forgive me. I've done a stupid and terrible thing." And
then he tells the story, the true story with the complete vow and what
he saw in Narcissa's mind.

What, based on our canonical knowledge of Dumbledore, which we know
includes total faith in Snape, would Dumbledore have said to him?]

Please don't answer this post if you think Snape would not have
confessed to Dumbledore. That's another thread altogether (the "Snape
is Evil, get over it" thread). Quote my arguments in the first part of
the post and move them there is you want to tear them apart, but
please don't ruin this thread by doing that here.

And please don't answer if you think Dumbledore escaped as a bumblebee
 or his death was faked in some other way. That, too, is for another
thread.

Answer only if you think that Snape really, against his own will,
killed Dumbledore (with or without a real AK), that his choices were
to keep his vow, killing Dumbledore and saving Draco, or to die
accomplishing nothing because both Draco and Dumbledore would have
been murdered by the DEs if he had broken his vow. 

And answer only if you think Snape either did confess or may have
confessed the whole truth. I only want to know what a good and wise
Dumbledore might have said to a troubled follower who has quite
possibly just doomed them both by making a vow he really had no choice
but to make.

Please don't turn this thread in another direction by responding only
to some other part of the post. (It's okay to respond to the first
part, too, but it's the portion in square brackets that I want to see
answers to.)

Carol, for whom Snape is as much a tragic figure as Dumbledore