Snape, Dumbledore, & Sirus

Because that's where the Dark Mark was...

And because McGonagall send Flitwick to tell him.

Read it again. Chapter 26, The Cave (pg 557)
"Yes, this is the place," said Dumbledore.
"How can you tell?" Harry spoke in a whisper.
"It has known magic," said Dumbledore, simply.
..Dumbledore continued to revolve on the spot, evidently concentrating on things Harry could not see..
...Twice Dumbledore walked right around the cave, touching...
He was surprised at the crudeness of the blood payment.

It goes on and on. Dumbledore had no idea of how to get into the cave, and had no idea of what he would find. He had certainly not been there before.
He DID take Harry with him, not knowing what to expect.

Psyduck, I concede the point that the whole of events from the cave onward were unexpected. Which just further emphasized what a brilliant wizard Dumbledor was to be able to identify the liquid on sight. Of course, it also brings out just how much more of a risk it would have been to drink it, unless Severus regularly kept an antidote to this particular potion in his stores. Somehow, I find that unlikely.

But I do have one question. Were Snape and RAB (who I think we all know was Regulus Black) close associates? And if so, could RAB have conveyed some information to Snape regarding the cave and what it contained or did not contain? Could this actually be a setup on Snape's part? Any thoughts?

Good idea. Maybe it was a setup by Snape. It was a good thought. Im rereading the book now, so when I get to the end I'll have to read it closly. But that is a good idea.

No, I doubt that Snape was pals with Sirius' little brother,
and I doubt that they knew each other well enough to conspire together against Voldemort.
And if they did, and Snape knew what Regulus knew about the cave,
why let Dumbledore bother going there at all? It was empty.

Unless you're saying that Snape is a bad guy after all.
But why would Regulus tell him anything?

If Snape is a good guy, he would have told Dumbledore that the horcrux was stolen.
If Snape is a bad guy, he would have told Voldemort tat the horcrux was stolen.
He didn't tell anyone, because he didn't know.

I'm too tired right now to explain it any better than that.
Is anyone following me?

And yet, RAB must have had an ally of some sort who would have enabled him to acquire the Horcrux in the first place. Dumbledor's solution to the liquid was to drink it. Do you think that Regulus would have been able to either drink it without help, force someone else to drink it, or have enough experience with the dark arts to circumvent a spell put into place by Voldemort himself? Remember, RAB is younger than Severus and probably not quite as well versed in the dark arts, so I think that a little unlikely.

This aid could come from only one of two places - the Order or a traitor within the ranks of the Dark Lord. It clearly wasn't an order member, because if it were Dumbledor would have known the locket was not there. The only other traitor we know of with the knowledge to get past the Dark Lord's defenses is Snape, who even then was a key player. I admit he may not have been the only traitor in the ranks, but he is the only one we know of who could have pulled this type of heist off. But if that is the case, it begs the question, "If it wasn't the real Horcrux, why didn't Snape tell Dumbledor?" Perhaps Snape wasn't as informed of Dumbledor's or Voldemort's plans as we might think.

I suppose Regulus could have hauled someone in there under Imperius, and forced them to drink the liquid for him, but it occurs to me that if you want to leave the Death Eaters you probably would not be using their methods. Especially since you would have to execute the person you had with you in order to keep them from giving you away. (Then again this might be exactly what happened considering Regulus was found out. He just didn't have the stomach for killing anyone else.)

The only other chance Regulus would have had to replace the locket would have been if the Dark Lord had entrusted him with setting up the traps in the cave in the first place. He then could have switched lockets before the traps were instituted. But did Voldemort trust one of his junior members that much? How much would he have told Regulus about the importance of the locket? And why would he have given RAB this info at all? Let's examine the short message in the locket.

"To the Dark Lord, I know I will be dead long before you read this but I want you to know that it was I sho discovered your secret. I have stolen the real Horcrux and intend to destroy it as soon as I can. I face death in the hope that when you meet your match you will be mortal once more. RAB"

From this short passage, we know that Regulus discovered the information on his own. So we are still left with a couple of questions. A- How did Regulus acquire the locket. and B- Is it possible he may have imparted his knowledge to someone else, either on purpose or inadvertantly.

Looking at it from a purely logical standpoint, the only way Snape could have had anything to do with that Horcrux would have been if he and Regulus were taking it to the cave before the defenses were in place. In this case, Snape would have been ignorant of both the objects purpose and the lack of authenticity when Regulus exchanged it. It is kind of hard to believe that one as intelligent as Snape would not have been able to figure this out, but then at the time he was probably still a loyal Death Eater who knew that questions were hazardous to one's health and obedience was king. Still highly unlikely in my mind.

Bottom line, Regulus had to have help from somewhere. It probably wasn't Snape. He and Snape probably only knew each other as black shapes across the crowded inner circle of a madman.

A popular theory is that Regulus took Kreacher and probably made him drink it.

Sorry, I didn't really read the rest...too long for me right now.

I dont know DD could be dead and Snape could be good. I think that DD Told Snape to kill him. That is the fight that Hagrid over herd
Also Sirius will be back 100%