The wording of the vow (Was: Hermione and 'Evil is a strong word' )

[justcarol67]

No: HPFGUIDX 165905

Carol earlier:
> <snip> She knows that Snape made a UV to *protect Draco*, 
> 
> a_svirn:
> not just protect, but *help* as well. <snip>

Carol responds:
Actually, no. Admittedly, Narcissa asked him to take the UV to help
and protect Draco, and Snape agreed to do so, but note how Narcissa
interprets "help":

"Severus--oh, Severus--you would help him? Would you look after him,
see he comes to no harm?"

To which Snape responds: "I can try." (HBP Am. ed. 35)

He's not saying, "I can try to figure out what he's up to and help him
do it," much less "I can try to help him kill Dumbledore" or "I can
help him fix the Vanishing Cabinets" (which he doesn't know about).
His whole objective is to try to keep Draco from being killed
(Narcissa's fear) and possibly to keep him from becoming a killer
(Dumbledore's objective, as we see on the tower).

And then Narcissa says, "If you are there to protect him . . . .
Severus, will you swear it? Will you make the Unbreakable Vow?" (35,
ellipses in original)

Snape, his eyes fixed on Narcissa's tear-filled eyes, calmly agrees to
take the vow (ignoring Bellatrix's taunt that he'll "slither out of
action" again). He can have only one intention, the one that has
already been stated, to protect Draco. (And "help," should she ask him
to do it, can be interpreted to mean "see he comes to no harm," or, as
we see Snape later trying to do: find out what he's up to, put his
cronies in detention, advise him against foolish actions like cursed
necklaces, encourage him to confide his plans. Draco refuses Snape's
offer of help, and nothing happens. The vow is not triggered because
Snape is not bound to help him.)

The vow itself (setting aside the provision about "doing the deed" if
it appears that Draco can't) asks him to *watch over* and protect
Draco, not *help* and protect him:

"Will you, Severus, watch over my son, Draco, as he attempts to
fulfill the Dark Lord's wishes?" 

"I will."

And will you, to the best of your ability, protect him from harm?"

"I will." (HBP Am. ed. 36, dialogue only)

Not a word about helping him do it. No commitment to help fix the
Vanishing Cabinet or let DEs into Hogwarts, nothing to prevent him
from discouraging Draco from attempting amateurish tactics that could
get him caught, nothing to prevent Snape from putting Draco's helpers
in detention.

If Snape had vowed to help Draco and "help" meant helping him with his
Vanishing Cabinet plan, Snape would have been dead long before the UV
forces him to choose between killing DD and dying himself. What it
does entail is keeping an eye on Draco--and saving him from Harry
Potter's Sectumsempra curse. He has clearly kept his vow to protect
Draco "to the best of his ability" or he'd be dead. (That provision is
still in effect on the tower, as far as I can see, which is one reason
why Snape snatches Draco by the scruff of the neck and makes sure that
he gets safely off the Hogwarts grounds.)

The third provision is, of course, another matter, but it doesn't go
into effect until Draco, face to face with Dumbledore on the tower, is
unable to "do the deed." That the "deed" is what Draco calls his "job"
(killing Dumbledore) and not his "plan" for accomplishing that
objective (getting the DEs into Hogwarts) is clear from the fact that
Snape doesn't even know about the plan (though I think he knows that
Draco has been spending time in the RoR and he's trying to get Draco
to tell him the plan) and from Amycus's words on the tower: "We've got
a problem, Snape. The boy doesn't seem able--" (595). Able to do what?
To "do the deed." 

The third provision, "And, should it prove necessary . . . if it seems
Draco will fail . . . will you carry out the deed that the Dark Lord
has ordered Draco to perform?" (36, ellipses in original). It does
indeed seem that Draco will fail, as Amycus's words indicate, but
Snape's hesitation suggests that he hopes it still won't "prove
necessary." Only after DD speaks his name, he and Snape exchange
glances, and DD repeats his name, followed by "please," does Snape "do
the deed." That action has nothing to do with "helping" Draco. It has
to do with watching over him, protecting him, and doing the deed that,
alas for them all, has proved necessary despite Snape's and
Dumbledore's combined efforts.

Carol, who could simply have quoted the vow to prove that "help" isn't
in it but wanted to emphasize the point