Viewing the evidence

[dungrollin]

A canon quibble, and a couple of lame attempts at answering good 
questions.

> Snape also was there for a job interview.

Dung:
Trelawney says that Snape "...was seeking a job at the time, and no 
doubt hoped to pick up tips!" (HBP p509 UK) No mention of Snape 
being there for an interview too. Of course, he *could* have been - 
but you wanted no interpretation, just bare canon.

> Voldy's interpretation of the prophecy points to the Potters and  
> Longbottoms and it is this that causes Snape to switch sides.

Dung:
No canon quibbles – just going boggle-eyed in shock...

> Did Voldy try a soft approach before resorting to death and  
> destruction? Is this where the "thrice defied" fits in? And does 
this link to Hagrid's comment "Suppose the myst'ry is why You-Know-
Who never tried to get 'em on his side before."?

Dung: Quite possibly - see also why Sirius' parents thought Voldy 
had the right idea before he showed his true colours.

> What exactly is Vapor!Mort?

Dung:
Don't think I can do this without a couple of assumptions, but I'll 
give it a go, pointing them out where I can.

(Assumption #1) The usual split is body/mind/soul and JKR mentions 
all three so I'm going with that. A soul-sucked person has no soul 
and (in the Potterverse) therefore no mind. A ghost has a mind but 
no body. (Assumption #2) Presumably a ghost still has a soul that 
hasn't passed on to wherever these things go, since you need a soul 
to have a mind, and they appear to be conscious thinking things. 
>From Diary!Tom, we see that even a small piece of soul is enough to 
have a mind. Vapour!Mort had a mind (since he can think well enough 
to build up a good stock of resentment towards his loyal followers 
while in exile) and a bit of shredded soul. So he was probably just 
composed of soul. In which case, why did he not look like a ghost?

Additionally, does a disembodied soul retain its magical powers?

The only power remaining to Vapour!Mort was possession, which 
doesn't require a wand (or he wouldn't have been able to do it.) DD 
states clearly that no matter how tattered Voldy's soul gets, nor 
how many hotcookies are destroyed, his mind and powers remain 
unaffected - to the extent that he's probably not even aware of 
their destruction. But DD also says that Voldy has no understanding 
of how powerful a pure and untarnished soul can be, which is 
somewhat contradictory. 

We never see any of the Hogwarts ghosts using magic, but Harry has 
never actually asked whether they can or not. It might be 
significant that although NHN has a ghostly ruff, he has no ghostly 
wand, and couldn't pick a real one up anyway. We have two choices, 
neither ruled out or in by canon: 1. Ghosts might still have their 
magical powers, and therefore be able to do 'uncontrolled wandless' 
magic (though it's supposed to emerge when stressed, and since 
they're already dead, they shouldn't be scared of much.) 2. There is 
something about dying and coming back as a ghost that stops you 
being able to access your magic. 

Ok, I give up on the strict adherence to canon altogether (that 
didn't last long), here's some speculation:
The Bloody Baron doesn't say much, does he? He's not quite as human-
seeming as NHN or the fat friar. One possibility is that 
when alive he was a murderer (he's the Slytherin ghost, he seems to 
have met with a violent end himself - it's not that much of a 
stretch), so his soul is more tattered than NHN's, which could be 
why he's less functional as a ghost. Which would explain why Vapour!
Mort was 'less than the meanest ghost' - his tattered soul was 
knackered from all the killing sprees.


And the biggie:
> Can the GH mystery be solved using the above canon with no need 
for additional assumptions? I know what I think - but that's for 
another post.

Dung:
The flippant answer is "ask again after book 7". A slightly less 
flippant answer is "we wouldn't be discussing it if we didn't think 
we had some chance." But really? I doubt it can be done without a 
lucky guess or two (perhaps no-one will, even then), hopefully 
guided by some themes and meta-thinking. 

Dungrollin