Manipulation in Potterverse and in general /Tigana spoilers

[pippin_999]

No: HPFGUIDX 185152

Carol:
 it's obvious that he not only expected but *intended*
> for Quirrell to try to steal the Stone. (Note that he is the only
> teacher of the five key subjects taught to all students--Potions,
> Transfiguration, charms, Herbology, and DADA--who was not asked to
> help guard the Stone, along with the loyal Hagrid.)

Pippin:
Quirrell did indeed help to guard the Stone. He supplied the troll. I
agree that Dumbledore knew that Harry would eventually try to retrieve
the stone. I don't think he intended that Harry should try to stop
Quirrell from doing so. Harry would have been no match for even a weak
wizard like Quirrell in a duel -- he was very fortunate that Quirrell
attempted to lay hands on him  before using a spell. 

Carol:
> What I don't understand is how DD knew that LV would attempt to
steal the Stone from Gringotts *before* Quirrell put on the turban.
(LV possessed him to "keep a closer eye" on him *after* he failed to
steal the Stone in the Gringotts break-in. 

Pippin:
Agreed DD *wanted* Quirrell to try to steal the stone -- it was the
bait in the trap he was setting, something Voldemort could not resist.
Since the protections had to be set up in advance, Quirrell probably
knew the Stone was coming to Hogwarts and  decided to try to steal it
from Gringotts before it could be fetched. His failure not only
disappointed the Dark Lord, it  was certain to put Dumbledore on his
guard. It was at that point that he was possessed. 

Dumbledore could not have known he was possessed before, since he
wasn't. The only outward change was the smelly turban. Quirrell was
obviously lying about why he was wearing it, but even if Dumbledore
guessed that the purpose was to hide the marks of LV's punishment, it
doesn't follow that he could guess what the punishment was.

Pippin