What were the Malfoys DOING there?

[Hannah]

No: HPFGUIDX 113584

> >  Hannah originally: 
> > >>>The real question here is what Lucius Malfoy was hoping 
> > to achieve with the diary. I can think of three possibilities:
> > 1. Restore LV to power through diary Tom
> > 2. Kill off as many mudbloods as possible, and get the school 
shut down.
> > 3. Discredit Arthur Weasley, hopefully killing some mudbloods 
along the way.<<<

> Carol asked:
> But wouldn't Lucius know (via Draco) that Voldemort had been in the
> back of Quirrell's head? Dumbledore tells Harry that "the whole 
school knows" what happened between him and Professor Quirrell 
(obviously an exaggeration, and what they knew was probably a 
distorted version),
> but surely the other students didn't think that eleven-year-old 
Harry had *killed* a teacher who was a secret Dark Wizard. (Quirrell 
died, as LV tells the DEs, when LV left his body--or rather, his 
head.)
> 
> Much later, in OoP, Harry mentions the inconvenient fact that
> Voldemort was "sticking out the back" of Quirrell's head (a remark 
for which Umbridge gives him detention), but it's clear that his
> Gryffindor classmates know this already. So wouldn't the rest of 
the school know it, too? Or wouldn't Lucius Malfoy have figured out
> something of the truth from the version of events that Draco gave 
him? I think that's how he knew it was time to bring the diary into 
action.

Hannah: This is a good question, Carol.  I always assumed that the 
students knowing 'everything' didn't extend to the presence of LV, 
and was surprised when Harry made that comment in OoP and got so 
little reaction.  Why wasn't more fuss made in the WW at the time?  
You'd think that they'd take LV's return more seriously at the end 
of GoF if they knew he'd nearly managed it a few years before.

As for its bearing on the timing of the diary incident, I think it 
probably wasn't related.  Dobby tells Harry at the end of July (one 
month after Quirrel!Mort is defeated) that he has known about the 
plot for months.  Unless Dobby is exaggerating, it seems likely that 
Lucius has been planning to use that book since before Quirrel!Mort 
and Harry have their confrontation.  

Tonks also replied:
> Well Malfoy is very upset when DD comes back to the school, so 
> getting rid of DD could have been his plan. But I have another 
> thought. How do we know that Malfoy Sr. knows what the diary will 
> do? Maybe he couldn't get a good price for it or that Knockturn 
> Alley store (can't remember name) would not take it. So he had to 
> get rid of it and it seemed like a good idea to stick it in her 
> book, might get her father in trouble instead of Malfoy. Maybe he 
> had no idea what it could do. If he didn't want LV back and didn't 
> know what the diary could do then he would not have known that it 
> could help open the chamber again. Maybe he just wanted to get rid 
> of something of LV's and not have it around the house.
> 
Hannah now: It sounds good in theory, but as I've said before, 
Malfoy hands out the diary *after* Dobby has warned Harry about a 
plot to make terrible things happen at Hogwarts, which he claims he 
has known about for months.  So Malfoy was definitely planning to 
use the diary to ill effect.