You've got to hand it to J.K.Rowling; she does a great job of hiding things in a really obvious way. What follows are shuffled-up excerpts taken from pages 728, 415, 725, 726 and 729 of my copy of Harry Potter and the Order of the Phoenix. Once I'd rearranged the pages into the only order that made any sense (it's obvious when you see it, isn't it?), the rest just fell into place ...
Harry sat bolt upright, stunned by Dumbledore's words. He hadn't realised how much Dumbledore had noticed over the years. Was there something? Was it possible that Harry possessed a power strong enough to defeat Voldemort? His thoughts whirled dizzily with confusion. Why did Dumbledore want to know about the paperclips? It seemed so random. Perhaps Dumbledore was getting old and confused -- like Uncle Vernon's Great-Aunt Mildred (who had spent the last myopic years of her life befriending all the lamp-posts near her house). At that moment the light fell on Dumbledore, upon the silver of his eyebrows and beard, upon the lines gouged deeply into his face ... Hang on ...
"Er ... Professor?" said Harry, looking away suddenly.
"Yes, Harry?"
"Um ... er ... is that -- I mean -- have you got glitter in your beard?"
Dumbledore looked a little startled at this, and quickly combed his beard out with his fingers. Sparkling motes of silver rained down over the desk.
"And in your eyebrows?"
"Oh, dear me ..." muttered Dumbledore, quickly brushing his brow.
"And ... " Harry leaned forward, squinting in the dawn light, "it looks as though someone's been drawing thick black lines down your face. Sorry."
Dumbledore now swooped down upon one of the fragile silver instruments whose function Harry had never known, carried it over to his desk, sat down facing him again, and paused for a moment.
"Yes," he said. "You're right, Harry. I am so sorry. I hope I didn't alarm you with my appearance. I was in the middle of trying out a disguise when I had to Apparate to the Ministry."
"A disguise?"
"Yes -- trying to make myself look old, you see."
Harry didn't see, but he'd never been one for asking the right questions. He pointed at the silver thing on Dumbledore's desk. "What does that do?"
"This? Oh, well -- it's a mirror, Harry. Shows me what I look like. Do you want to try it?"
Mirror. Harry had heard of them, but he'd never actually seen one before. He reached eagerly across the desk.
"Careful, Harry! It's mostly glass, you know!"
An angry young face staring back at Harry from the mirror. Was this what he'd grown into?
"My hair!" he gasped. "It's a mess! And those glasses! I look like a right idiot. No wonder I don't have a girlfriend. Spots ... Yeuch!"
"Anyway," said Dumbledore. "Weren't you about to explain a few things to me, Harry?"
"Oh yeah, right," said Harry, putting the mirror down. He licked his palms and smoothed his hair down. "Better?"
"Very neat," said Dumbledore. "Now -- the Marauder's Map?"
"There's not much to tell," said Harry. He thought back, wondering what exactly Dumbledore wanted to hear. "I let Moody -- I mean that Crouch man -- use it in the Goblet of Fire. Is that what you mean?"
"Did he give it back to you?" asked Dumbledore.
"No ... no, he didn't. Now that I think of it, I just had it there with all my other school stuff when I came to pack things up at the end of the year. I must have gone and got it from his office, though, mustn't I? I can't remember much about that week, to be honest."
Dumbledore sighed, and said, "Perhaps that's for the best, Harry."
"Why do you want to know, anyway?"
"Tell me about the Firebolt first, if you would."
The Firebolt ... Had anything weird happened with the Firebolt? He remembered how strange it had been when he got the Firebolt -- but that had all been sorted out, hadn't it? It was from Siri-- No. He wasn't going to think about -- about -- not yet. He rallied himself. What was he supposed to be thinking about? The Firebolt. Maybe ...
"Ron kept borrowing it," he said. "In the Prisoner of Azkaban. And in the Goblet of Fire. Almost every week, I reckon."
"Go on," said Dumbledore, a note of excitement in his voice.
"That's it," said Harry. "He kept on borrowing it, but I never had to ask him to give it back to me. 'S a bit weird, isn't it?"
"In what way?" said Dumbledore. He seemed to Harry to be practically bursting with encouragement and suspense.
"Well," said Harry slowly, "normally you'd expect people to forget sometimes, but Ron never did."
"And what does that mean?" said Dumbledore, practically leaping out of his chair.
"I dunno. I suppose -- that Ron's a really good mate."
Dumbledore deflated, and said, "Right, of course, Harry. Maybe you'll realise more as you tell me about the quill."
"I've only got one quill," said Harry, his voice suddenly loud and strong; white-hot anger leapt inside him.
"There is no shame in what you are feeling, Harry," said Dumbledore's voice. Harry blinked. Dumbledore hadn't moved his lips. "On the contrary ... the fact that you can feel pain like this is your greatest strength."
"Is it my special power, though?" asked Harry, not at all interested in how Dumbledore's voice had apparently taken on a life of its own.
"No," said Dumbledore's voice, just behind Harry's left ear.
Harry was tempted at this point to throw a bit of a tantrum. Dumbledore was always so vague! He felt as though he was caught up in some stupid guessing game where Dumbledore had all the answers. Suddenly he wanted to know everything -- about his parents, about his money, about Voldemort, about his role in all of this.
"Is there anything you want to ask me, Harry?" said Dumbledore's voice, from underneath a vase.
"No," said Harry. He frowned.
"The quill," prompted Dumbledore.
"Right." Harry felt the white-hot anger lick his insides, blazing in the terrible emptiness, filling him with the desire to hurt Dumbledore for his calmness and his glitter and his empty words. "Hermione is always borrowing my quill, and she's got loads of quills! LOADS! And I've only got one quill."
"And ... ?"
"And what?"
"And do you always have that same quill?"
"Well, yes." Harry had no idea what Dumbledore was getting at. "I wouldn't get very far with my schoolwork if I didn't have a quill, would I?"
"And yet Hermione is always borrowing it ... "
Finally Harry could see what Dumbledore was getting at. Like Ron, Hermione always made sure to return whatever she had borrowed. She was thoughtful, considerate -- a true friend. He blushed, but it was hard to tell if that blush was because he was embarrassed in a friend way or in a love way.
"I understand," he said, looking up. He could see now that Dumbledore looked sad and tired. "Professor?"
"What?" said Dumbledore, glancing sharply into Harry's eyes. He smiled. "Sorry, Harry. I was just trying out another disguise -- looking sad and weary. Did it work?"
"I would've said it was more sad and tired actually, Professor."
"Oh well. Nevermind. So, now that you understand -- I trust the reference to paperclips has become clear?"
Harry smacked his own forehead in frustration. He'd forgotten about the paperclips!