Another possible reason Snape killed DD

[Deb]

No: HPFGUIDX 135340

Gail wrote:
 "Several posters have pointed out how odd it is that DD pleads with 
 Snape at the end (the implication being that he's pleading for his 
 life.)  I agree that he may indeed be pleading for Snape to kill  
him -
- that would be much more in character.
 But why? Here's my theory:  
 Remember that DD insists Harry fetch Snape when he is ill from the 
 potion, not Madame P. or anyone else.  Could it be that there is a 
 secret only he and Snape share? 
 Keep in mind how strongly DD insists that Harry obey him without 
 question on their outing to the cave, even if it should mean 
leaving 
 DD in danger.  What if he had extracted a similar promise from 
Snape?
 What if the potion DD drank had put the horocrux into him, DD? When 
 he said "Kill me" in his stupor, it was because he knew this?  And 
 that Snape killed him because it was the only way to kill the 
 horocrux?"

Deb writes:
  I agree that DD tells Snape to kill him, and I agree that they 
probably shared many secrets. But what motivation would DD have at 
that moment to tell (and IMO DD is telling him, as he has on other 
occasions to "Please get on with it, do what I told you to do". 
Pleading, well maybe a little, but he trusts Snape and yes, I think 
they have an agreement or two or three between them)  Snape to kill 
him? I think it is related to the cave, the lake, the liquid DD 
drinks... and to what DD strongly believes is worse than death. My 
guess would be that DD thinks that a living death... like a Inferi, 
zombie, or someother entity that is dead but kept animated to do the 
bidding of a Dark Lord..... would be much worse than death! There 
has been some speculation about what was in that bowl ... what if it 
was the potion, or first part of a spell, that creates 
Inferi... "corpses ... dead bodies that have been bewitched to do a 
Dark Lords bidding."... as DD tells Harry on their trip to 
Slughorn's house.  

  So what if the liquid is the Draught of Living Death... mentioned 
several times in previous books. DD tells Harry it won't immediately 
kill him, and says once back at Hogwarts that he has come 
back "after a fashion".  Or if not the potion in the bowl then the 
water in the lake... DD tells Harry 3 times not to touch the 
water.... perhaps his warning is more than just not wanting to "wake 
up" what dwells beneath the surface of that vast lake. For it seems 
to me that under this lake dwells LV's army.... an army of Inferi. 
The corpses of most of the people he (and maybe the DEs) have 
murdered or caused to disappear during his reign of terror. Too bad 
Harry wasn't carrying a back pack and some bottled water... But he 
just splashes the water from the lake onto DD's face .... and 
perhaps DD hopes that that will not activate the Inferi curse... 
 
So Harry gets DD back to Hogsmead and DD wants Snape right away for 
his superior knowledge of the Dark Arts.... and Potions. I suspect 
he is hoping, or knows, that Snape has an antidote to whatever it 
was that he drank... or is carrying a bezaor(though Snape said in 
the very first Potions class that bezaors will protect one 
from "most poisons"... so maybe it won't work on all poisons). But I 
also suspect that there is a time component... that the antidote 
must be given quickly... and he does not get to Snape fast 
enough ... so when he is lying there on the tower, and Snape comes 
through the door, the only thing left to save DD from becoming one 
of LV's Inferi is for Snape to kill him. 

 And Snape, having promised to save DD from this terrible fate, is 
angry beyond measure, that this has come to pass ... and resolute in 
his determination to save DD from a fate worse than death.   

  Deb