Harry is sitting in a cafe, quietly reading the paper, when in comes a teenager with an uncanny resemblance to a vampire and an annoying tendency to use long words...
A boy of seventeen sat at the counter, reading a newspaper. He was tall with dark hair and owlish glasses. If you looked closely, you could see a jagged scar on his forehead. His startlingly green eyes scanned the paper.
Behind him, the door to the coffee shop swung open. The boy named Harry Potter glanced around. Entering the coffee shop was a skinny, pale youth who looked about a year younger than Harry and had an uncanny resemblance to a vampire. Harry reached for his wand, in case the kid was a vampire. He'd never heard of a child one, but you never knew, what with Lord Voldemort back and Inferi turning up everywhere. However the boy seemed to be human, and Harry relaxed. The kid was unnerving though. Harry was a living legend in the wizarding world, and was used to people watching him, but this muggle stared at him like he was an interesting lab specimen. Harry turned back to his newspaper, but continued to feel those piercing eyes on him. Finally he turned around angrily and shouted, "Whaddayouwant?"
The boy held out his hand. "Salutations. My name is Artemis Fowl. Butler, my, ah, butler, tells me I should initiate more interaction with others of my generation, though personally, I am against this course of action. What is your name?"
Harry hadn't understood half of what this annoying kid Artemis had said. Artemis... wasn't that a girl's name? "Go away," he replied morosely."
"I shall ignore your uncourteous remark as I assume your name to be, ah, 'Harry Potter'? What a peculiar title."
"How do you know my name?" Harry growled, outraged. And Artemis Fowl isn't exactly a normal name either, he added silently.
Artemis walked over to Harry and flipped over his newspaper. With a growing sense of doom, Harry saw the kid point to a page -- the Daily Prophet newspaper. Under an enormous headline reading 'Harry Potter: The Chosen One?' was an equally enormous picture of Harry that smiled and waved. Like all photographs in the wizarding world, it moved. "Interesting use of an LED monitor," Artemis remarked.
Harry knew he was in trouble. This boy would have to be mind-wiped. But first Harry had to get him somewhere not so public, which meant using the Imperious Curse. He leveled his wand at the smiling Artemis and muttered the incantation. A ray of light streaked towards the kid.
And bounced off his sunglasses.
Harry ducked as the curse rebounded. He straightened up to see Artemis smiling. "As you are probably now aware, I know how to deflect mesmer". He tapped his lenses. "Mirrored glasses do the trick."
Harry cursed under his breath and a jolt of lightning struck the floor. He grabbed his paper, wondering what to do now. Artemis smiled a vampire smile. "Now then, Mr. Potter, do try to be more civil."
"Who are you?!"
Artemis smiled. "Artemis Fowl the Second," he said. "The world shall remember my name." Then he was gone.