[GraceCoolidge]

That's an interesting theory! I try not to think about Kreacher more than I can help, though. The interesting thing about your idea is that Kreacher might have been able to use the boat as well without "registering" as a wizard, as Harry did. I have heard some people speculate that Kreacher hoarded the locket, too.

I was half expecting Dobby to die in the most recent book. Glad he's made it okay so far.

[JenB]

Precisely. Plus it's someone who's devoted to Regulus, but who wouldn't happen to mention to a member of the Order, "Oh, we took this little trip and found this cool locket, think it means something?"

By inference, whoever helped Regulus (assuming he didn't find some way around the potion all by himself) is dead, because neither Voldy nor Dumbledore knew the Horcrux was gone... dead, or not important enough for anyone to listen or talk to... like a house elf, especially a nutty evil house elf who's been sealed up by himself for years.