Why did Snape take the UV?

[zgirnius]

No: HPFGUIDX 157248


> a_svirn:
> But if he didn't know about the task then the whole point is moot. 
> Carol argued that he did know in which case he couldn't help but 
> anticipate the third provision, IMO. 

zgirnius:
I know, I know, this is an old discussion, but I am just catching up 
after my vacation...

I disagree. I think Snape was expecting a different third and final 
provision. (I would bet Unbreakable Vows are always done in threes.) 
Narcissa had already suggested Snape could do it, and he had refused. 
He *then* suggested to the distraught Narcissa that he could help 
Draco, and she seized on that idea. 

And help is nice and ambiguous. There would definitely have been 
wiggle room in such a Vow for a Snape loyal to Dumbledore.