Sometimes Greg Lestrade wondered why he became a policeman, so much running around, cleaning up messes and paper work. Not to mention the terrible work hours that had pretty much cost him his marriage. However right now, as he pushed his way through the overcrowded tube station his thoughts were more accurately:

'Why did I let that bitch take the car?'

He weaved through the heavy throng of people trying to make his way to the platform when he felt something slip into his pocket. Without thinking he twirled around and caught a small hand, which was holding his wallet. He immediately loosened his hold when he noticed his would-be pick pocket couldn't be any older than seven and looked positively startled at being caught.

"Nobody's ever caught me before." the boy blinked, he seemed unnaturally calm about the entire affair aside from being momentarily surprised by Lestrade's quick reflexes.

"Yeah, well you picked the wrong target kid." Lestrade grumbled, the boy's eyes widened.

"You're a policeman, a detective inspector." He whispered, it was a miracle Greg could hear his voice over the hundreds of people walking by.

"How did you-never mind, come on kid. You're in big trouble." Lestrade pulled him lightly but the little boy dug his heels against the ground and pulled.

"No! Let me go!" He demanded trying to pry Lestrade's hand away from his wrist.

Of course he would make a scene.

"Listen kid, it's the law I have to take you to the station and call your parents, or at least take you to station security." He sighed, the boy just tugged harder.

Lestrade took in his appearance, he was very skinny, to the point of being unhealthy and his clothes were thick and patched. He had dark curls that looked as if they hadn't been cut in quite a while, nor had they seen a brush or soap. A runaway perhaps?

Unfortunately as he was thinking about this his grip must of shifted and in his distraction the boys thin wrist jerked free. The boy tumbled backwards onto the smooth tile floor and quickly fled, cursing under his breath Lestrade followed.

The kid was quick, he'd give him that, his thin frame wove through the crowds with ease while Lestrade was left pushing and bumping into people left right and centre. Luckily the crowd was more organized as he made his way to the platform following the dark haired boy, who was constantly looking over his shoulder at him. Finally he cornered him at the edge of the platform, he expected him to turn and face the inspector, but that isn't what happened.

Lestrade felt horror wash over him as he child jumped straight off the platform down onto the metal tracks, some people around him screamed and pointed.

"Kid get out of there!" he yelled, "The tunnels only fit the trains, if you run down there you'll be crushed!"

As if fate decided to be ironic the sound of a whistle and a faint light appeared at the end of the left tunnel, heading straight for the kid. However, unlike the adults in the station the boy didn't seem fazed and without a word slipped under the concrete overhang at the edge of the tracks. Just in time too as the train came zooming into the station before stopping to let people on.

Lestrade let out a breath he didn't know he was holding. The overhang was a small hollow area under the platform where somebody could fit in case they fell on the tracks. At least the boy was safe, if not in even more trouble than before. It seems his little chase through the station had alerted security and several officers were at his side by the time the train began to move off. However when they jumped down onto the tracks to retrieve the boy they found the overhang empty.

"How's that possible?" Lestrade asked, "Where could he of gone?"

"There's some cracks in the concrete at the edge here," one of the officers called, "My guess is it that the kid slipped through into the maintenance corridors."

"We'll send somebody down there to take a look, that's no place for a kid." The head of security promised before bidding the inspector goodnight.

Lestrade wanted to help the officers search for the boy in the tunnels but he knew he'd be of little help and probably end up lost anyway. Instead he vowed to take the tube again tomorrow and keep an eye out for the child.

-oOo-

He didn't see him again, not straight away. After another two weeks of catching the tube he was beginning to think that perhaps the boy had been picked up by child services or something. Though station security informed him they hadn't found him in the tunnels, in fact there was no sign he'd even been there.

Greg didn't know why he was letting it worry him so much, so he'd had a scuffle with a pick pocket, big deal. The child shouldn't of been on his mind so much. He was about to try and take his mind off things with a cup of coffee from the tube canteen when he heard a yell.

"Get back here you brat!"

He turned and saw a familiar pale face with black hair run past him with a large man in pursuit. Looks like his little pick pocket was at it again. Quickly he flashed his badge to the man.

"I've got him!" He ensured and took off, this time the boy headed away from the platforms, towards the stairs and the street, however at the last second he veered right and flung open a maintenance door. Lestrade followed, the hall was dusty and darker than the bright white tile of the station but he could still see he followed the little shadow through the thin passage way. He could hear the boys breathing he sounded panicked, he was probably the only one to actually follow him this far.

Glancing behind him the boy saw he was still being follow and dropped to the ground a few feet from Lestrade, before the inspector could make a grab for him he'd yanked the face of an old venting shaft off and jumped inside. Lestrade cursed, at first he thought he'd lost the boy but then he realized he could still hear him. The shaft was old and creaky, he could hear the soft thumps of hands and knees as the boy climbed. Smiling to himself he walked as quietly as possible, following the sounds until he came to a wall and a door, the boy was in the room beyond.

Slowly, he turned the handle and opened the door, he found himself on a metal walkway suspended over a large room, there was the dark haired boy sitting against the wall by an old abandoned track. The old London line, the new tube stations had been built over them back in the 70's. The only light came from a large round metal container stuffed with newspapers and various other odds and ends that had been set alight. The child perked up as he heard the click of the door and glanced around, but didn't see the inspector standing a few feet above him.

"John?" he called tentatively with a small shake in his voice, "John is that you?"

Lestrade jumped down, landing in front of the boy and giving him such a shock that he tumbled backwards.

"Sorry, just me." He greeted, the boy started to shuffle backwards until Lestrade held up his hands in surrender.

"Hey, I'm not here to hurt you." he smiled, "I just wanted to get that man's wallet back."

"Will you leave if I do?" the boy asked suspiciously, holding the piece of leather to his chest.

"I can't just leave you down here in the dark." Lestrade argued.

"I'm fine, I don't want to go with you, I want John." The boy pouted, "And I need this money."

"You can't just take other peoples things." Lestrade tried inching forwards only to have the boy scramble back.

"Fine, I give it back and you leave, but let me keep five pounds." The boy pleaded, "Please?"

That made Lestrade stop. Five pounds? Surely he'd want more than that.

"It's for John." The boy explained, some how knowing exactly what Lestrade was thinking.

Lestrade was about to ask who this 'John' was when a light flicked against the walls of the old station and voice echoed down the empty halls.

"Sherlock? Sherlock, are you here?"

It was the voice of another, older child. The little dark haired boy, whom Lestrade guessed was Sherlock smiled.

"John! John there's a man! He's trying to catch me!" he cried.

Lestrade opened his mouth to object but he realized Sherlock was actually correct, he hadn't been about to leave without the boy in tow. Footsteps echoed around the corridors for a few seconds before another floor flew around the corner, flashlight and backpack in tow.

Sherlock jumped to his feet and instantly was at the other boys side fisting his hands into his coat. Lestrade once again opened his mouth to reason with the two but to his surprise the older boy reached into his pocket and fished out a large knife and pointed it at the inspector with murderous eyes.

"I'll only ask once." He said darkly, "Did you hurt Sherlock?"

I have no idea if there really is an old London line, I just made that up for the sake for the story :P And if there is one, well yay for me! :)

Also this story is set in modern times, I dont have an EXACT date but somewhere in the 2010-2012 area, it;s not pertinent to the story.