The Opening Chapter of Book 6

[vmonte]

No: HPFGUIDX 103945

Eustace_Scrubb:

I think JKR said the person who finds he/she can do magic late in life
will do so under "desperate circumstances." (sorry don't have the
exact citation but I'm certain she used a phrase close to this) While
Dudley may feel that being threatened by Harry fits that phrase, I
doubt that JKR would have termed it so--unless Harry has truly lost it
and is really going to try an Unforgiveable on his cousin, which I
can't see happening.

I also favor either Petunia or Dudley as the late-blooming
witch/wizard, but I suspect the talent will appear as a result of an
attack by Death Eaters--who will not be expecting any magical defense.
(I doubt that spontaneous magic will do much good against LV himself
or Dementors, but given that many of the DEs seem to be a brick shy of
a load I think a late-blooming Dursley stands a chance of thwarting
them.)

vmonte responds:

I favor Petunia as the late blooming witch.  I also think she will 
take a DE (or DEs)unawares.

 From my post:
http://groups.yahoo.com/group/HPforGrownups/message/100964

Dudley relives a lost memory from his childhood through the Dementor
attack. I think that the Dementor that attacked Dudley made him
remember something he saw as a baby.

>From OOTP (Page 30, U.S. version): "All dark," Dudley said hoarsely,
shuddering. "Everything dark. And then I heard....things. Inside m-my
head..."

Petunia then responds in a way that makes it seem that she is worried
that her son may be losing his mind:

"What sort of things did you hear, popkin?" breathed aunt Petunia,
very white-faced with tears in her eyes.

But maybe Petunia was worried that Dudley might have remembered
something that happened in the past. Something he should not have
seen.

"But Dudley seemed in capable of saying. He shuddered again and shook
his large blond head, and despite the sense of numb dread that had
settled on Harry since the arrival of the first owl, he felt a
certain curiosity. Dementors caused a person to relive the worst
moments of their life...What would spoiled, pampered, bullying Dudley
have been forced to hear?"

Petunia may have been threatened by Voldemort. She probably knows him
up close and personal, and not by listening in on her sister's
conversations. Voldemort may have gotten to Petunia (when he was
searching for the Potter's) before he reached word from wormtail. He
may have threatened Petunia or her son with a dementor. In fact
Dudley's worst memory may be that he previously had an encounter with
a dementor as a baby! (I don't think that Dudley's worst fear was
getting a pigtail.)

Dudley may realize the fear he caused to others while he was a bully
and may give Harry important information from his vision. (Rowling
has said that she feels sorry for Dudley because his parents actions
towards him amounts to child abuse and that they have not prepared
him for the real world.)

Rowling has stated that someone will gain magical powers late in life
and that it is very rare in the wizard world. Petunia and her family
may be put in another life and death situation and Petunia's magic
may emerge. She may end up killing someone important to the death
eaters because she takes them unawares.