Character Analysis
Shmoopers, let's soak up all the Dumbledore goodness we can in this film, because, well...just trust us, okay?
(Sob.)
Wizardly Bromance
Dumbledore and Harry clock some serious bonding time in this film. Harry has now heard the prophecy (which Dumbledore already knew about, as is his wont), so the cat's out of the bag: Harry knows he has to be the one to kill Voldemort.
As a result, it appears that Dumbledore is more into the idea of letting Harry in on some of the steps he's taking to fight the Dark Lord. Seems only fair, since Harry has to be the one to finish him off, right? Any hope of protecting Harry from too much knowledge or responsibility was probably out the window when Harry heard that prophecy, wethinks.
Dumby asks Harry to help him with one particular mission this school year: getting a guy named Horace Slughorn to admit the truth about a conversation he had with Voldemort back in Voldy's school days.
First, the headmaster takes Harry to meet Slughorn and convince him to come back to teach at Hogwarts (which Slughorn eventually does), and then he asks Harry to get close to Slughorn to get the intel he needs. Harry eventually succeeds at that as well.
It seems like Dumbledore and Harry are quite the dream team, eh?
Secret Missions
That all said, Dumbledore does keep some secrets from Harry. For example, at around the time of the Hogwarts winter break, he goes traveling without telling Harry where he's going. In fact, he doesn't even tell Harry he's leaving; he has Snape do it (maybe to avoid questions he doesn't want to answer?).
Harry eventually learns that Dumbledore went in search of an object that was likely to be of great importance to Voldemort...and then destroyed it. Unfortunately, that whole process left Dumbledore with some kind of ganky scarring on his hand.
The Final Mission
Dumbledore has Harry accompany him on his next expedition. Once Harry has gotten Slughorn to spill his secrets, they realize that these dark objects Voldemort has been creating are actually little bits of his soul. Yup: he's basically been dividing himself up to make sure he's harder to kill. Pretty hardcore stuff (especially since you create these objects by murdering people. Shudder.).
Dumbledore has an idea of where the Dark Lord may have hidden another of these objects (called "Horcruxes"), and this time, he takes Harry with him to find it. He's aware of what a big ask this is:
DUMBLEDORE: Once again, I must ask too much of you, Harry.
Harry is totes up for it though, and this rather grueling outing shows us just how much the bond and trust between these two has grown. They both ask a lot of the other to get their hands on that Horcrux. Dumbledore has to drink a bunch of potion that makes him suffer terribly—and Harry has to make him do it:
DUMBLEDORE: It's your job, Harry, to make sure I keep drinking this potion. Even if you have to force it down my throat. Understood?
We have—oh, we mean, Harry has—a really hard time watching Dumbledore suffer—and then forcing him to keep going—but he keeps up his end of the bargain. In the end, they are both rewarded for hanging in there: They get the Horcrux. High five, people.
The End
Unfortunately, right when they get back to Hogwarts, Malfoy and some Death Eaters show up to attack Dumbledore. Dumbledore then orders Harry to hide while he deals with the issue. Harry isn't super keen on that idea, but again, he trusts Dumbledore, so he says okay.
We're pretty sure he doesn't feel like his trust is rewarded this time around, though. While he's hiding, Snape comes upon him, wand drawn. He gestures at Harry to be quiet. Harry agrees...and then Snape pops up and reveals himself to everyone. And kills Dumbledore, even though the headmaster begs him not to:
DUMBLEDORE: Severus. Please.
That sounds like a plea for mercy, right? What else could it be?
We know that Dumbledore always thought Snape was on his side, no matter how shady the prof acted, but we're finding that hard to believe right now. Uh...friends don't kill other friends, right? Harry has tried to trust Snape up to this point, but that seems to go out the window as soon as Snape sends the killing curse at Dumbledore.
Of course, Dumbledore was big on secrets and only revealing things to Harry in due time, so maybe there's more to the story here...but because of Dumbledore's untimely death, Harry will have to piece it together on his own from this point on.
Ugh.
Dumbledore's Timeline