Albus Dumbledore: the myth and the man

[vmonte]

No: HPFGUIDX 96194

Pippin wrote:
Is it? Dumbledore could know from Ollivander that Tom Riddle is
Voldemort. He knows Tom Riddle opened the Chamber last
time. It's a good bet people were petrified last time. (Dippet
refers to "all these attacks" but only one person was killed. ) He
knows Voldemort is laying for Harry. He knows that the Chamber
monster was never caught. Even if his portrait spies aren't
keeping an eye on Malfoy manor, wouldn't it be prudent of him to
lay in a supply of mandrake root?

vmonte responds:
Weren't the mandrakes acquired before anyone was petrified at school? 
(I hope what I'm remembering isn't movie contamination.) If the 
Chamber was still closed (and we go with the theory that DD is not 
all knowing), then DD didn't know that Voldemort was at the school.
So why buy mandrake?