The confession that Harry had been hoping for didn't come right away. His parents, though a little more distracted than usual, were perfectly jovial when they arrived home after their clandestine meeting at the inverted pyramid. There was a slight strain to the air, but neither James nor Lily Potter seemed at all inclined to answer their son's unspoken and burning curiosity about what had happened.

And, of course, Harry wasn't able to ask anything himself, for to do so would require confessing that he had overheard a conversation that he shouldn't have, after sneaking into a part of the city where he shouldn't have been. Both admissions would likely land him in serious hot water, and Harry had an aversion to being in trouble.

So he had no option but to stay quiet and wait until his parents were ready to let him in on their little secrets. But Harry had secrets of his own, special places he had found around the city where he could go to be on his own. And he was on his own a lot, which he didn't mind so much as he didn't know any different.

One such place was high up on the sheer wall in the very West of Pont-y-Annwn. A crude sort of staircase had been cut into the side of the rock, or maybe it had just worn down that way after centuries of use. Harry wasn't sure about this, but his active mind liked to imagine all sorts of subterranean creatures beavering away with pick-axes and shovels as they mined away, though what they might be mining for Harry couldn't conceive.

At the top of the stairway the rock levelled out onto a narrow parapet, giving a sweeping view of the whole city from up here. Harry would sit for hours, dangling his legs over the ledge and looking across at the huge towers of The Spike and The Pickle, whimsically named after sister buildings in surface London hundreds of miles away, and fighting sickening bouts of vertigo if he ever felt brave enough to look straight down over the edge.

For it was a long fall to the streets far below … almost a thousand meters, some guessed, from floor to roof. It was a height almost impossible to believe, considering that the whole enormous chasm had been artificially hollowed out deep beneath the surface of the Earth, which was yet higher still through seven miles of solid bedrock.

But that wasn't the only thing that Harry found impressive about his home, and one of the other major reasons was the cause for the High Parapet being the favourite of his secret places, and the thing that had drawn him here today. He took his favourite seat on the ledge and his gaze quested across to the sweeping vista of The Light Deck … the array of hundreds of brilliantly lit, giant glass globes that provided illumination to the city down below. That was a truly impressive sight, but Harry's goal was something else entirely.

For a new species of insect had found a way to evolve and thrive down here in the perpetual darkness. It was a special type of moth that fluttered and snapped, thousands of them, around the globes of the Light Deck, absorbing the light and then changing it to different colours. It was the most mesmerising thing, to watch all of the reds and blues and golds flash and sparkle against the backdrop of that palpable blackness.

"Beautiful, aren't they?"

Harry slammed his head so hard to his right that his neck ached in protest. Then he scrambled up in his surprise, away from the ledge and backed into the wall, where he huffed hard for a clean breath of air. For there was a stranger up here with him, a tall man in a long cloak that Harry had been quite unaware of until he was suddenly there. He might as well have popped out of thin air, such was the abruptness of his appearance.

And his appearance was what drew Harry's attention first, once his shocked pulse had calmed down enough for sense to return to his mind. For Harry had never seen anything like this man in his life, and it was unlikely that anything even remotely close had ever been seen in Pont-y-Annwn before … and if this man ever was seen, he'd likely be carted away by the authorities to have tests run on him, such was the bizarreness of his attire.

Oddly, it was this quirkiness that settled Harry's nerves.

For this Stranger, whoever he was, was tall and spindly, a fact obvious even though his deep purple cloak covered his head in a monastic-type hood, and then ran right down to the heels of his hob-nailed, buckled boots. And he was clearly old, ancient even. Harry could see wisps of silvery hair poking out from beneath the velvet rim of his hood.

"I find them fascinating, don't you?" the Stranger went on chattily. "The moths, I mean. I study them to try and better understand their bio-luminescent properties."

"What's bio-luminescent?" Harry asked with a furrowed brow.

"The ability of animals to create their own light," the Stranger explained. "It is quite common among deep-sea creatures, but less so in other ecosystems. Perhaps the dark of the ocean floor and the dark of this underground world drive evolution in the same way."

"Are you a biologist then?" Harry asked, taking a tentative step forwards.

The Stranger chuckled. "Of a sort. Let's just say that I study the natural world and all of it's wonders."

"Do you know why they give off colour, the moths, I mean?" Harry went on. "It's pretty cool to watch, but why do they do it?"

"We can only speculate," the Stranger observed, thoughtfully. "It could be to attract a mate, to mark territory … or even for defence."

"Defence?" Harry queried. "How is that defending themselves?"

"Would you like to see?"

Harry nodded eagerly. The Stranger chuckled at his keenness and reached into his cloak, drawing out what looked like a silver cigarette lighter. Then he held out his other hand as if in beckoning, and sure enough one of the moths floated down and landed deftly in the Stranger's open palm. The creature was electric emerald green in colour, and sat quite docile as the Stranger flicked open the top of the cigarette lighter and pushed a button that was exposed there.

And then, in a rush as if a vacuum had opened up, the colour shot from the moth and was captured in the chamber of the cigarette lighter. The moth now looked dull, oddly naked, and almost totally invisible.

"Cool," Harry hushed in reverence.

"Cool, indeed," the Stranger chortled.

"Does it hurt them?" Harry asked, peering close to look at the now semi-translucent creature before him.

"Not at all, they do this naturally to themselves," The Stranger explained. "They eject their colour to avoid detection. It is very difficult for a predator to catch prey that they cannot see."

Harry nodded as he understood. "I think I'd like to be able to turn invisible. I could go anywhere then."

"And where would you like to go most, if you had the chance?"

Harry stared out, almost longingly, at a vast tunnel cut into the rock just visible on the other side of the city. A single rail track led into the tunnel, and beyond to who-knows-where.

"There," Harry muttered, pointing at the train track.

"But that leads to the surface world," the Stranger reminded him with more than a little hint of warning.

"I know," Harry replied. "And I've always wondered what it's like up there. My Mum and Dad tell me that it's full of dangers and that they can't take me to see it, but I'd still love to go one day."

"It is dangerous … a place of war and plague," the Stranger agreed. "But it also a place full of wonder and majesty … and enough mystery to occupy even the most curious of young minds."

Harry felt the Stranger smile at him, but he still couldn't see his face beneath the hood. Even so, the act put Harry at ease.

"That's why I'd like to go," Harry went on. "Maybe it's because I'm the only child down here, but I've always had the vague sense that this isn't my entire world, that there's … more. I don't know what, exactly, but I just have the feeling that the answers are up there."

Harry pointed through the ceiling towards the world above.

"And I hope one day that you find those answers, Harry," the Stranger replied.

Harry turned his head slowly. "I … I didn't tell you my name."

The Stranger didn't move, but his manner was still perfectly at ease. "No, you didn't."

"Then how do you know it?"

"The more interesting question would be to ask why I know it," The Stranger returned in a cryptic tone. "For that is a story far more thrilling and exciting."

"Then tell me that one!" Harry insisted. "Tell me how and why you know who I am, tell me who you are, tell me everything!"

"Would you really like me to?" asked the Stranger, his voice fizzing with electric energy. "Would you like me to set you to task on solving this particularly tricky riddle that shadows your life? For if you do, you'd better go and ask your parents first."

"Then let's go now!" Harry cried eagerly, as he started back down the rugged staircase. "There's something funny going on and it's about time they told me what it is. And if they don't, you should."

"Alas, I cannot come with you, Harry," the Stranger told him. "But now that you have made this decision, I will be in touch."

"But how will you know what my parents say? You haven't even told me your … name."

Harry's final word drifted from his lips in hushed surprise. For as he turned to address the Stranger, Harry found that he had simply vanished into the gloom.

Had he jumped? Harry looked over the edge of the staircase and could see nothing. There was no Stranger-shaped splat on the streets down below. And there were no other ways on or off of that parapet, and the Stranger certainly hadn't passed Harry on the way down. He was just … gone.

And Harry had no idea what to make of it, though as he strode back to the parapet to investigate further, his toe stubbed against something metallic on the floor ... it was the silver cigarette lighter! Harry knelt and picked it up, wondering if the Stranger and dropped it as he disappeared ... or left it on purpose, for Harry to find in order to return it to him one day.

Either way, Harry pocketed the Put-Outer in his jacket and vowed that he'd do all he could to find it's owner again.

And hundreds of miles away, in a draughty room of an old castle in remote Scotland, a bespectacled old woman was drawing a sheet of heavy parchment towards herself, dipping a raven-feather quill into a pot of emerald green ink, and then placing a satisfied tick right next to the name of Harry James Potter, then smiling to herself as she sipped on a cup of Earl Grey tea.