Dumbledore's Silvery Sign

[entropymail]

>> "Should I go get someone?" said Harry. "Madam Pomfrey?"
"No," said Dumbledore swiftly. "Stay here."
He raised his want into the air and pointed it in the direction of
Hagrid's cabin.  Harry saw something silvery dart out of it and streak
away through the trees like a ghostly bird.  (GoF, ch 28)<<

In the interest of stumping The Old Crowd, I came upon this passage in
GoF, and just had to ask:  What do you think flew from Dumbledore's
wand?  Was it some sort of message, protection, spell? And,
consequently, who or what was it for?

I've got a few of my own ideas but, frankly, they're a mess. Maybe you
guys can make some sense of  it.

:: Entropy ::