Harry Potter and the Goblet of Fire, J.K. Rowling

Goodreads says:
It is summer holidays and soon Harry Potter will be starting his fourth year at Hogwarts School of Witchcraft and Wizardry. Harry is counting the days: there are new spells to be learnt, more Quidditch to be played, and Hogwarts castle to continue exploring. But Harry needs to be careful - there are unexpected dangers lurking ... 
Cries hard!!! Oh I love this book don't get me wrong but the ending is.... If you've read it you know why I'm crying, if you haven't.... what are you waiting for?? Okay no seriously (no pun intended) something bad happens to someone in this book (trying to not give away to many spoilers here) one particular scene has me in tears every single time: When you know who (no not Voldemort) asks Harry to do you know what. Confusing if you haven't read the book or seen the film right?^^
I've only just realized, rereading the books and everything that we see something that is important in future books (wow I seem to be realizing that alot!! :))
In this scene:

He raised his wand 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.

But I am confused as to why Harry doesn't recognize the silvery thing that comes out of the wand, it's not like he hasn't seen it before.
Right now I hate the Lestranges!!!! Why?? (another confusing thing if you haven't read the book)
And poor Draco, allthough he totally deserved it!!!^^
So I'm of to read the Order of the Phoenix.
See you next time^^