What is the purpose of the green potion?

[eloise_herisson]

So what is the purpose of the potion?

Ostensibly, the potion is there to guard the Horcux. This is beyond 
dispute. But why that method? We don't know exactly how the ring was 
protected, but evidently it was a different method.

Dumbledore tells us that Voldemort would have wanted whoever stole 
the Horcrux to survive long enough  for him to find out how he had 
managed the theft. Speculation amongst various posters that the 
potion forces memories to the surface reinforces the idea of 
interrogation, but there are a couple of problems with this, from my 
POV.

If Dumbledore is correct, then Voldemort needs to be aware *and 
quickly* that the Horcrux has been taken.  If Voldemort knew that the 
original was stolen (leading to RAB's death*) then either 
a) he would have recovered  and re-hidden it or 
b) he would be actively looking for it. 
The latter is quite a significant thing to become aware of only in 
the last book. 

Ostensibly, Voldemort believes that the real Horcrux is in the 
basin.  Is he aware of the violation yet? Wouldn't he have 
immediately sent his minions to bring back Dumbledore alive? If he's 
not aware, then what is the point of a potion that will keep the 
victim alive for just long enough to tell all?

I'm not sure I believe Dumbledore on this occasion. I believe it is a 
convenient fiction foisted on him by the dastardly author.

What does the potion actually do in terms of the book?

1) It provides an obstacle to retrieving the Horcrux
2) It becomes a test for Harry's loyalty to Dumbledore
3) It potentially makes Harry an agent of Dumbledore's death
4) It produces some intriguing dialogue
5) It produces a Dumbledore dependent on Harry's help (and in David's 
view thus enlightens us as to DD's greatest fear)
6) It complicates the issue of what exactly killed Dumbledore

Now JKR could have chosen a different method of protecting the 
Horcrux that would have resulted in 5 and 6 , ending up with a 
debilitated Dumbledore arriving back at Hogwarts in dire need of 
Snape's help. What ever method was chosen, it was bound to be 
something dangerous and involving Harry at all was likely to end up 
with some element of 2 and 3. 

The thing *specific* to the potion is that it evoked Dumbledore's 
strange ramblings. ~And that Harry heard them. What Dumbledore says 
is not secondary to the use of the potion: I believe that JKR used 
the potion specifically to provide a vehicle for what he says. In 
which case the words *are* significant to future plot developments: 
they are not the memories of the Inferi, they are probably nothing to 
do with RAB (whose identity is important only in terms of helping 
Harry to find the locket). I personally doubt, true or not, that JKR 
will ever spend time exposing Puppetmaster!DD so his remorse over 
past decisions will be neither here nor there in terms of the plot 
development.

Which, as all roads inevitably do, leads me right back to Snape.

~Eloise


*I wonder, particularly in view of Dumbledore's opinion that only a 
very great wizard was capable of getting through the enchantments 
guarding that Horcrux, if RAB didn't steal it after it had been 
hidden, but was instead the one sent to place it in the basin in the 
first place.