Who is Lucius Malfoy's informant?

[hfakhro at nyc.rr.com]

No: HPFGUIDX 21401

Really good questions! According to Dumbledore at the end of the 
book, Lucius sets TMR's diary on Ginny specifically because she is 
Arthur Weasley's daughter, and he is trying to overturn the Muggle 
Protection Act (I'm not sure that's the name) that Arthur Weasley had 
just submitted. Although you're right in saying how on earth was 
Lucius to know when the Weasleys would be going to Diagon Alley. The 
question is what are Lucius' real motives? Is it just to get Arthur 
Weasley or is it something Harry-related? If Lucius' intention was to 
get Ginny and her father in trouble, what does Harry have to do with 
that? I suppose he reasoned that TMR would go after Harry...

I see what you mean about Narcissa in a way, because it seems Draco 
had no idea either. Do you think Lucius talked to TMR via the diary 
and Dobby witnessed this? The whole Dobby thing is still a mystery to 
me - I know that the reason he came to warn Harry was because he is 
Harry Potter and he rescued house elves from something really bad 
by 'defeating' Voldemort. The other thing is, and I was never able to 
figure this one out - why does Lucius bring Dobby with him when he 
comes back to Hogwarts at the end of the book? There seems to be no 
reason given for this.