Disclaimer: I don't own Numbers or anything associated with it. This story is for entertainment only.

A/N: This is just my take on why Don might have become an FBI agent.

I'm not positive what the age difference between Don and Charlie is, but the consensus seems to be about five years so that's what I'm using.

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It was a warm summers day as four year old Charlie headed out towards the driveway. Armed with some new chalk he was almost bursting with anticipation at what awaited. Like any other four year old boy, Charlie loved playing with chalk. Loved plopping himself down on the concrete and spending hours drawing in white, blue, pink and yellow. Only stopping when it became too dark to see, or when one of his parents demand he come in for dinner. When he returned he was always met with bemused looks from his family. Surprised that someone so small could make such a mess. Covered from head to toe in chalk dust and dirt. It was one of the only times Charlie looked like a normal little boy.

Charlie wasn't normal though. Any person walking down the street would see what looked liked a normal little boy drawing on his driveway with chalk, but on closer inspection they would see something quite unusual indeed. Instead of pictures full of trees and houses and cars, Charlie's chalk drawings contained numbers and not kids stuff either. Real math, beyond the understanding of even the smartest passer-by. In fact Charlie's numbers were so advanced that most people assumed they were just scribbles, copied by an innocent four year old from something he'd seen his older siblings do. Charlie was oblivious to all this, as any four year old would be. Just happy to do the things that made him happiest. And that just happened to be algebra.

It was algebra that Charlie started to do on that summers day. Starting at the top of the driveway he was almost half way down an hour later, and was feeling very pleased with himself. He couldn't wait to show his mum and dad, and Don. Especially Don. His concentration was only broken when a dirty white baseball crash landed only inches from his small left hand. He watched as it rolled down the slope and landed in the gutter. Scrambling up he ran down and retrieved it. Holding it in his hand, he examined it's smooth surface, subconsciously starting to count the red stitching.

"Drop it, dork."

Charlie spun round so fast he lost his balanced and dropped the ball back into the gutter. His eyes resting on Eddie Williams, his brother's best friend. Eddie didn't like Charlie. He thought Charlie was a baby and was annoyed when Don's parents would make the two boys include him in their games. Charlie had no concept of the kind of fun that Eddie liked. He liked playing rough and Don would frequently return from Eddie's house brimming with smiles and bruises. But with Charlie they had to play 'nicely'. And more than once Eddie had 'accidentally' been too rough and made the little boy cry. Earning him the punishment of being sent home, unable to play with Don anymore. To Eddie, Charlie was a nuisance.

Recovering from his shock, Charlie bent over to pick up the ball again, only to be pushed aside by Eddie, landing on the road on his hands and knees. After getting the ball, Eddie turned to the small boy and laughed. Charlie did his best to hold back tears as he pushed himself up, only to be pushed back down by Eddie, who laughed even louder at his new game. Now Charlie's tear were of frustration. Even at the tender age of four he could see how unfair Eddie was being. He was five years older than Charlie and almost twice as big. Two more times Charlie tried to stand and Edie pushed him back down again. Tears now flowing down Charlie's face.

"Eddie, what are you doing?"

Charlie sighed in relief as Don finally made an appearance. And smiled to himself when he saw the look of momentary panic on Eddie's face.

"Nothing, I'm just helping Charlie up, that's all. He fell over. Little kids aren't very good with balance."

Eddie bent down and Charlie flinched as he thought he might hit him. Instead he grabbed Charlie's arm and dragged him to his feet. Before he let him go, the older boy squeezed his arm tightly, letting him know who rules they were playing by. Once free Charlie forced himself to smile at Eddie and mumble a 'thank you' in his approximate direction.

Although the genius gene hadn't passed on to Don the way it had his younger brother, he was no fool. Don knew the tension that existed between his best friend and his younger brother. He eyed Charlie closely.

"Are you okay?"

Charlie knew that question wasn't a straight-out 'is he hurting you?' kind of a question. But more of a 'can you deal with this on your own?' question. Charlie knew that Don didn't like always having to protect him, so he nodded and said everything was fine. Don seemed satisfied with that answer and took Charlie's arm. He was much gentler than Eddie had been and led his brother back up the driveway. Before heading back inside with Eddie he gave Charlie a stern look.

"Don't play on the road. Mum will kill me if you get hit by a car."

Charlie nodded and watched as the two older boys walked away. Just able to hear Eddie tell Don that his little brother, "is such a freak."

He sighed and looked down at his work, the excitement of it seemed to be gone. He sat down, legs crossed with his little arms on his knees and his head in his hands. A very adult-like pose for such a small person.

This was how the man from the van found him. Charlie was vaguely aware of the white van pulling up across the street and a man in jeans, black t-shirt and blue baseball cap climbing out of the driver's side. It was only when the man walked over to Charlie, stopping in the gutter where he and Eddie had just been, that Charlie recognised his presence. He looked up at the man who was smiling down at him and felt himself blush self-consciously.

"Hello there."

Charlie felt very small sitting underneath the tall man's gaze and struggled to get up. Once he was standing he noticed that the man had moved up the driveway and was only a few metres away from him. Subconsciously Charlie took a step back and turned his head towards the house. Again when he turned back to the man, he was even closer than before, but he was still smiling and Charlie couldn't help but smile back.

"What's your name?"

Charlie blushed again, happy that someone, anyone, was paying attention to him and not being mean.

"Charlie."

The man smiled bigger than before and Charlie found himself staring into his clear blue eyes and feeling...something. He couldn't explain it, but something told him that this man was here for a reason, a special reason that had to do solely with Charlie. And the four year old found himself buzzing with anticipation.

"Charlie, that's a nice name. A nice name for a nice boy. I bet your a nice boy, Charlie."

Despite himself Charlie giggled and that seemed to make the man even happier.

"Hey Charlie, how would you like to see something exciting? It's in my van over there." The man waved his arm towards the van on the other side of the road.

Exciting? Charlie cocked his head to one side trying to figure out what it could be. What was exciting to him? For any other little boy it would have been ice cream or puppies or even possibly a dragon. But to Charlie there was only on thing that was exciting and as the realisation dawned on him he almost jumped with delight.

"Is it numbers?"

The man's smile faded slightly as he also went through a moment of confusion. His own realisation dawning when he spotted the drawings beneath their feet. As he met Charlie's eyes again, his smile was as bright as ever.

"You guessed it. You really are a smart little boy aren't you?"

At that Charlie almost burst with joy. After the hostility of Eddie and the indifference of his own brother, he was so happy that someone had come just to see him. And they had brought maths, Charlie's ultimate favourite thing in the whole world.

"Would you like to see it?"

Unable to speak, the little boy just nodded his head. At that the man stood up and offered Charlie his hand. Charlie hesitated slightly, something in the back of his brain starting to take shape. Something important. But Charlie couldn't recognised it yet so he took the man's hand and they headed down the driveway.

Charlie was a genius. A child prodigy. His head full of things at age four that most people wouldn't know at age thirty. But still in his brain there was a small part that wasn't full of numbers. That instead was filled with chalk and cartoon and licking the bowl after his mother made a cake. With fear of the bogey man and the things under his bed, and delight at how Don could make a coin disappear into thin air. And it was this part of his brain that started screaming at him as they reached the road.

The voice of his mother in his head.

"Don't ever go off with strangers. Not even if they offer you candy and ice cream."

Don's voice joining in from the background.

"Or math."

Almost involuntarily Charlie let go of the man's hand. The man stopped, not smiling anymore.

"Charlie!"

Don's voice cut through Charlie's world. In the back of his mind he registered something in Don's voice, something he had never heard before. A kind of fear that he heard in his own voice when he called for the protection of his older brother. Charlie turned to see Don standing frozen in the doorway. Don was scared and if Don was scared then there must be something really scary happening.

Charlie didn't see the man turn to grab him, only feeling the ground beneath him disappear, and hearing a high pitch scream fill the air. Was Don screaming?

Don saw the man grab Charlie. Had seen the man holding his little brother's hand and walking him away from the house. A fear exploding inside of him as he raced to the front door.

By the time he got to Charlie the man was almost at the van. Charlie was screaming, terror in his eyes as they found Don's. Anger taking the place of fear inside of Don, wanting to tear the man apart for hurting Charlie. He threw himself at the man, forgetting for a moment that he was only a nine year old boy, not even five feet tall. Despite this disadvantage, Don fought valiantly. Wrapping his body around the man's right leg, he felt the man stumble. He was unaware of what was really going on until he felt the impact of something heavy falling on his shoulders. Stunned and winded he let go of the man's leg and found himself lying on his back on the road. The world around him full of yelling and screeching tyres.

The only thought in his head was Charlie. Scrambling up he saw his four year old brother sitting a few inches away. He had his hands out, palms up and they were covered in bloody grazes. Tears covered his face as Don grabbed him and held him close. Both were oblivious to the fact that they were sitting in the middle of the road and that most of the neighbourhood were now with them.

Don held Charlie until someone forced him to let go. He fought against the hands that tried to pull his brother away from him. Only finding comfort when his father gathered him up in his arms and hugged him tightly. Whispering that he had saved his brother, and that he didn't have to fight anymore. Don watched as the police arrived, followed by an ambulance. The paramedics wanted to take Don and Charlie to the hospital but grudgingly agreed to let their parents drive them. Don holding Charlie's hand all the way there and back.

When Don was sixteen he found out that, that summer the man had taken three other little boys before he tried to take Charlie. He had raped them, murdered them and left them in a warehouse. Despite both Don and Charlie being interview at length by the police, the man was never found. Charlie was the last little boy he tried to take, after that he disappeared. No one ever told Charlie.

That thought stayed with Don even after the day itself started to fade. Decades later as he sat at his desk in the FBI building, looking at the mug shot of the latest criminal to be put away by the brothers Eppes, he couldn't help but feel like he had unfinished business. He knew that the man could easily be dead now or at least an old man. It had been over 25 years ago.

Don was no fool. He realised that it wasn't about that particular man anymore, wasn't even about Charlie anymore. It was about all the men of the world who would prey on all the Charlies of the world because of their innocence and vulnerability. And it was up to all the Dons of the world to stop them. He was just one link in a very big chain.