cave potion refill...possible flint?

[urghiggi]

No: HPFGUIDX 174939

OK, whole new subject.

I'm puzzled how the cave potion came to be refilled after RAB  took the locket horcrux and 
substituted the fake locket.

According to DH, the sequence of events vis a vis the cave was as follows:

1) LV asks RAB for the 'loan' of Kreacher for an apparent dry run of his locket horcrux 
safety engineering scheme. According to "Kreacher's Tale," LV and Kreacher go to the cave, 
LV makes Kreacher drink all the potion, and then ".... He [LV] dropped the locket into the 
empty basin... He filled it with more potion. And then the Dark Lord sailed away...." 
Kreacher disapparates from the Inferi-filled lake and returns to Grimmauld Place, where he 
reports to RAB what he has seen.

2) RAB returns to the cave with Kreacher and a fake locket. RAB drinks all the potion that 
LV had replaced after the first incident. Kreacher switches the lockets when the potion is 
gone. The Inferi drown RAB when he drinks from the lake. "And he drank -- all the potion 
-- and Kreacher swapped the lockets -- and watched ... as Master Regulus ... was dragged 
beneath the water... and ...." Etc. Kreacher returns home as ordered with the real horcrux, 
and says nothing to anyone. 

3) Dumbledore and Harry go to the cave. The basin is full of potion. The fake Horcrux is at 
the bottom. DD drinks all the potion, HP tries to get lake water for him and riles the inferi, 
DD rallies to fight off the inferi with fire. "Dumbledore scooped the locket from the bottom 
of the stone basin and stowed it iside his robes...Dumbleore led Harry back to the boat." 
There's nothing more about the basin or potion in this scene.

My problem -- according to Kreacher, LV actively "filled it [the basin] with more potion" 
during the initial dry run & potion consumption. Why did he need to do this? Because in 
order for there to have been potion there for DD to drink in incident 3 (HBP "The Cave," the 
basin would have had to refill ITSELF. LV could not have gone back to do it after RAB 
consumed it, because LV, in "DH: The Final Hiding Place", clearly has no idea that the 
locket horcrux has been switched for a fake one. "How could the boy, or anybody else, 
know about the cave or penetrate its protection? The idea of the locket being stolen was 
absurd...." Later, LV struggles to choose which horcrux site to visit first, with the cave 
being among the candidates. He had no idea anyone had been there after his first visit 
with Kreacher.

If the basin had to BE "filled" (as Kreacher indicates) rather than filling itself, then it 
should've been empty after RAB drank it all. There shouldn't have been any potion there 
for Dumbledore to drink.

Tell me what I'm missing here. Sure looks flinty to me... like something a continuity editor 
ought to have caught....

Julie H, Chicago