Chamber of Secrets, and powers Dumbledore knows not

[dracojadon at yahoo.co.uk]

No: HPFGUIDX 171814

Oh! I forgot to add: what are the "powers Dumbledore doesn't ...  
powers no decent wizard ..." that Dobby talks about? Dumbledore  
doesn't what -- know about basilisks? Memory preservation? (That  
strikes me as exactly the sort of thing DD would know about.) He  
certainly knows about the Chamber of Secrets: he was there last time  
it was opened.

Is Dobby, possibly, talking about horcruxes? (All right, Dumbledore  
knows about them too, but Dobby would be unlikely to know that.)  
Parts of HBP were originally to be CoS. Could Dobby have known the  
diary was a horcrux without Lucius knowing, and been masterminding  
something of his own? _Was_ there, perhaps, a more complex plot,  
which didn't unfold? Except, what would be the literary point of that?

And in any case, what can a horcrux do on its own?

Jadon