Why did Snape take the UV?

[a_svirn]

No: HPFGUIDX 157058

> Tina:
> 
> Maybe Snape was calculating a bigger risk – Voldemort being 
informed 
> of their conversation. Especially after Snape interrupted Narcissa 
> saying he knew about the plan, if he didn't (or even if he did, 
but 
> wasn't supposed to). It doesn't seem to be very ooc for Bella to 
ask 
> Voldemort why he trusted Snape with that information.

a_svirn:
Actually, I'd say it would be rather awkward for Bellatrix to bring 
up the subject. Because it would mean a) that she (not just 
Narcissa) did discuss with Snape something that shouldn't have been 
discussed, and b) that she was insolent enough to demand 
explanations from her Lord. 

> Tina:
> By agreeing with the Unbreakable Vow, Snape is making sure their 
> conversation never reaches Voldemort, since Bella seems to love 
her 
> sister enough not to want to put her in trouble. 

a_svirn:
If he was banking on Bellatrix's love to anybody, but Voldemort he 
was taking insane risk.

> Tina:
Before the Vow, 
> Bella wouldn't have a strong motive to hide Narcissa's motivations 
> to go to Spinner's End – she was desperate, and she wanted Snape 
to 
> help her protect her son, but she didn't *do* anything. If Snape 
had 
> refused, nothing serious would have happened and no one could be 
> accused of interfering in the big plan, therefore the conversation 
> wouldn't necessarily have to remain a secret between the three. 
With 
> the Unbreakable Vow, everything changes. Now Narcissa *is* 
> interfering in the plan, and Voldemort could punish her for that.

a_svirn:
Wait a minute, so you think that Snape anticipated the third 
provision? Because just by agreeing to protect Draco, he did not 
interfere with the big plan. 

> Tina:
> So, yes, the Vow is too great of a risk for a DDM Snape, but it 
> could seem at the time a better alternative. 

a_svirn:
A better alternative ... to what? Earning Voldemort's displeasure? 
There was a better solution for that – sending Narcissa packing 
without promising her anything. This would make the most perfect 
sense especially if he knew about the plan. This way he would have 
nothing to explain to Voldemort.