AN: I do not own either HP or Shadowhunters or the Mortal Instruments.

Harry landed with a thump on the recently rained on grass. He glanced up at the sky, noting the clouds and the sun, and sighed in relief. He had taken Death up on its' offer to get away from the wizarding world, to get away from people who hero worshipped him. Though it had been 300 years since he had killed Voldemort, he still liked planets that were similar to his own.

He continued to look around the place he had landed in, aware of the power or energy that radiated from several miles away. He narrowed his eyes, whispered a spell under his breath and zeroed in on the city that lay maybe a hundred miles away.

The city looked really beautiful, gleaming and shining in the mid afternoon sun. It was definitely the source of the power that he felt and after a moment of concentration, he could feel warding around the city. Warding that would keep out what, he didn't know.

A cry drew his attention behind him and he turned, dropping his hand to the elder wand in his pocket. It sounded like a child… Harry's heart skipped a beat at another cry, able to hear it because of the enhanced senses that he had given himself.

There was a little cottage a mile away, tucked against a circle of trees. The cottage backed up to a small forest and he could see a big lake beyond the cottage, maybe thirty miles away. The lake though… The power coming from the lake was luring him in for something and Harry wasn't entirely sure what it was.

Another, louder, cry made up his mind and he turned away from the lake and hastened towards the cottage.

Jonathan tried to keep silent as Valentine hit him again, bringing his left hand up to his mouth and biting the skin, leaving his right hand to brace himself against the side of the house. He could already feel blood streaming down his back from the whip that Valentine was using, flinching minutely. At a particularly sharp hit, he let out a strangled whimper.

"You have to be strong, son," Valentine stated, as he whipped him again. His back hurt so much and he hoped that his father hadn't discovered that Jonathan had hidden his stele again. He had done it to draw Valentine's attention and now… he had it. The nerves in his back cried out again, the pain reverberating through his body.

"Downworlders won't give you a second chance."

"I'll be good, father."

"You will be," Valentine ordered, his voice full of warning. "I won't have a weakling for a son."

Jonathan winced again as he heard the whip fall down on his back again and couldn't restrain a cry. Sweat dripped onto his back and black spots overcame his vision. His hands shook and his legs trembled at the strain of keeping himself upright.

"What the fuck is going on here?"

Jonathan heard the whip drop but stayed where he was, unsure what his father wanted him to do.

"Who are you?" Valentine questioned. Jonathan heard him turn around, facing the strange man who had interrupted them. The man who had gotten past Valentine's wards.

"Someone you do not want to mess with."

"You're from the Clave, aren't you? He's a demon child. This is for his own good."

"Right…"

Jonathan's heart skipped a beat at the unknown man's voice. It sounded like the man was about to turn away but… He almost wanted to shout for help but he knew Valentine would whip him even more. Shadowhunters didn't ask for help. They had to be strong and ready to kill at any moment.

"Demons. You talk like they're a thing here," the strange man remarked. "Still no excuse to whip a child like that."

Jonathan shivered at the underlying steel in the man's voice.

"I could pay you to walk away," Valentine offered. "I am very rich."

"Yeah, that won't work with me," the man said. Jonathan heard him take a footstep towards Valentine. "My, my. You're raising two children like this. As soldiers. This stops now."

Valentine let out a noise that almost sounded like a growl, picking up the whip and turning. "Warlock."

"Wizard, thank you very much."

Jonathan heard Valentine make a strangled noise and then silence emanated in the clearing behind the house. He heard soft booted footsteps walk up towards him and felt his heart beat fast.

"Hey, kid. You can turn around. It's okay."

Jonathan hesitated, unsure if this was a test by his father or not.

"What's your name? My name's Harry. Valentine's not going to hurt you anymore."

Jonathan finally, slowly, turned around, taking care of his back. His eyes widened at the sight before him. Valentine was frozen right in front of the strange man, not a part of him moving. The man… Harry was kneeling before him, green eyes soft with concern. Harry had wild black hair that reached down to his shoulders and a scar on his forehead.

"Are you a Shadowhunter?"

Harry shook his head. "No. I'm not a Shadowhunter. Are you really a demon child?"

"My name's Jonathan and I'm eleven. I don't know. I can kill things with a touch," Jonathan offered. "Do you want me to kill something for you?"

Harry blinked, his lips twitching into a frown. "You can kill things with a touch."

"Yeah."

"May I take a look at your back? I can give you something to ease your pain," Harry finally said, looking him over.

Jonathan stared at him, looking for any hint of hate or judgement. Valentine had said that his mother had left because she hated him and was scared of him. Harry wasn't looking at him weirdly or like he was about to flee. The man looked concerned, worried for him.

"It does hurt," Jonathan whispered, inwardly telling his knees not to buckle and show weakness. But maybe Harry didn't care about showing weakness. Maybe…

Harry nodded, pulling a trunk out of somewhere and opened it. Jonathan saw him look at Valentine, who was still frozen, and then peered back down at Jonathan. Harry reached his whole arm into the trunk and Jonathan blinked, staring at the man.

"What… What kind of magic is that?"

"This trunk has a limitless expansion charm on it," Harry offered, his arm coming out with a small container of what looked like paste. He looked at Jonathan before opening the container, smearing some of the paste on his fingers and gesturing for him to turn around. "This should numb up your back, ease the burning sensations."

"You're not afraid of me?"

Harry stared at him, shook his head. "No. Should I be?"
"I killed a stray cat by touch last year," Jonathan murmured, looking right into Harry's green eyes. "Valentine encouraged it."

Harry held out his other hand towards him, the one that didn't have paste on it. His shoulders were loose and relaxed as he looked at Jonathan. "Go ahead. Take my hand."

Jonathan stared at him then reached out, placing his fingers on Harry's palm. Harry sucked in a sharp breath but otherwise didn't react. Jonathan could feel something going on but it wasn't the same thing that happened with the stray cat. Or with the werewolf.

"Here, turn around. I'll clean up your back and smear some of this on your back," Harry remarked quietly then something softened in his eyes. "I'm not going to hurt you, Jonathan."

Jonathan turned around, hesitant but unsure whether his legs would hold him up for any longer. He heard Harry whisper something under his breath, something that was in a language that was faintly familiar and the blood he could feel on his back vanished. Harry whispered something else, in that same language, and his skin tingled. Fingers touched his back and his skin cooled off, erasing the burning pain of being whipped.

He sighed in muted relief and his knees buckled, Valentine's voice back in his mind saying something about Shadowhunters and weakness.

"Do you have another parent, Jonathan? Someone you can live with?"

"No. Valentine said that Jocelyn hated and feared me. He said that people wouldn't… couldn't love me."

"Jocelyn? Your mother?"

"I don't remember her. Valentine took me away several years ago."

"Well. My godfather married a werewolf and people loved them both. How about you stay with me until I can find you a good home?"

Harry withdrew his fingers from his back. Jonathan turned around and looked up at him, thinking about what Harry had said. He wondered what the difference between Harry and a warlock was. Harry had appeared out of nowhere. "You would let me live with you?"

"Of course. Now… What to do with Valentine…" Harry trailed off, peering at Jonathan then over to where Valentine was. "How about you grab whatever you want from your home and meet me back out here?"

Jonathan nodded, his back now painless and his legs steady enough. He took one last look at Valentine, the older man's face stuck in a snarl, before racing into the home that they had shared.

Harry stared down at the man Jonathan had called Valentine. He had already skimmed the man's surface thoughts and that alone had set his heart racing, his body shuddering. Valentine was planning on doing many things, genocidal things, in the future. Child abuse was just a waypoint on the way there.

Valentine had already sent one child away from him, another child named Jonathan. Though from what Harry had seen, that Jonathan wasn't actually Valentine's son. The boy had ended up with the Lightwoods, a Shadowhunter family.

He whispered the incarcerous spell, watched idly as ropes bound the still petrified Valentine. If he was going to stick around on this world, it would be useful for him to know what was what in it. He glanced to the home in front of him and then placed his trunk on the ground, resized it, and opened one relatively small compartment. The main compartment served as his home while he was traveling but he did have a smaller room. One for detainment, that could only be opened with parseltongue.

He cast a featherlight charm on Valentine before picking up the man, none too gently, and strolled down into the trunk, glancing around the small room that more or less mimicked a jail cell. It had a bathroom and such, a bed, but someone inside it could only leave with Harry.

He deposited Valentine onto the bed, pulled out a box of vials that was right next to the bed, and pointed his wand at the man's temple. He whispered a spell that he had developed over the years, the elder wand warmed in his hand, and watched as all of Valentine's memories copied themselves and were sucked into the vials next to the bed.

It took several minutes, enough that Harry could hear Jonathan yell out for him, saying that he was ready. The spell was still active so Harry spelled Valentine asleep and walked back out of the trunk, peering down at Jonathan. The boy only had a small pack with him, a thin piece of metal sticking out of one of his pockets of his jeans.

Jonathan had thrown on a black, long sleeved shirt and his short blond hair waved in the slight breeze. The boy had green eyes now but when he had touched Harry, his eyes had turned all black, probably the demon blood in him.

Harry shrunk his trunk and tucked it in a pocket.

"You ready?"

Jonathan nodded, taking a step closer to Harry, who knelt down.

"Let's get out of here."

"Where's Valentine?"

"He's dead. I killed him," Harry offered, holding out a hand.

Jonathan blinked but didn't say anything, just closed the distance between them and burrowed into Harry's arms.

"I'm going to apparate us," Harry whispered, wrapping his arms around Jonathan, feeling him shiver a little. The whip that Valentine had held when Harry had appeared was still on the ground, still sparkling with that odd metal. Harry flicked his fingers, watched as the whip exploded into small bits. "Close your eyes?"

Jonathan stayed quiet but Harry could hear as his breathing evened out, hear his movement.

The doorbell rang just as Jocelyn was sitting down to dinner, Clary and Luke already at the table. Simon was sitting next to Clary, the two of them talking of school and of Simon learning how to play the guitar.

Luke raised an eyebrow at Jocelyn and she shook her head, her hand reaching for the angel blade that was no longer there. They weren't expecting anyone or anything. Luke stood up and walked through the hallway of the small brown house and over to the door.

"Mom?" Clary asked, looking at her with a question in her eyes.

"We're fine, sweetheart. It's probably Dot again," Jocelyn remarked, hearing Luke talk with the person at the door.

"I like Dot," Clary replied, smiling and getting up, about to race for the door.

"Why don't you start eating? Food's just going to get cold," Jocelyn said, not wanting Clary to get anxious.

"Yeah. The food's already getting cold. You said you didn't like cold meatloaf," Simon responded, elbowing Clary and drawing her attention.

Jocelyn stood up and joined Luke at the door, her eyes widening and freezing when she saw the man at the door.

The man who was holding a young kid in his arms and just as Jocelyn walked up, the kid turned around, showing Jocelyn his green eyes. Familiar green eyes.

"Who the hell are you?" Jocelyn questioned, her eyes narrowing dangerously.

"Jocelyn?"

"That's Jonathan," Jocelyn hissed, peering at the man holding her son. Her demon son. She took a step backward, back from Valentine's son.

Luke gasped, his eyes flashing blue, before he crossed his arms, inhaling deeply.

"I thought he was dead!" Jocelyn retorted.

Jonathan's eyes widened and he turned, burrowing into the man's chest. The man, with a similar shade of green eyes and wild black hair, not to mention a scar the shape of a lightning bolt, stared at them. Jocelyn watched as his arms tightened around Jonathan.

"He's just a child!" The man exclaimed, his green eyes narrowed and practically glowing. "A child."

"He's not just a child! He's part demon!"

"Mom? Who's that?"

Jocelyn turned around, seeing Clary and Simon walking up to them. "Clary, I told you to stay at the dinner table."

Clary frowned, peering up at Jonathan, who had turned back around. "Hello."

Jonathan looked at Jocelyn, his own green eyes wide with hurt. "Hello."

"I'm Clary. Do you want some dinner?"

As if on cue, Jonathan's stomach growled.

"He's your son, Jocelyn," Luke reminded quietly, out of the earshot of Clary and Simon, and peering at the man curiously. "What was your name again?"

"Harry Potter."

"Fine. Come in. You two can stay for dinner," Jocelyn gritted out.

Harry stared at her, his body still, almost if he was some kind of animal ready to pounce in protection of a child. Luke watched as he peered down at Jonathan, the two exchanging some kind of silent communication, before Harry lowered Jonathan to the floor.

"Here. Come on. We're having meatloaf and it's great," Clary said, smiling widely at the thought of a new friend. She held out her hand towards Jonathan and he took it. Jocelyn inhaled sharply but nothing happened.

"If you like meatloaf anyway," Simon whispered as he followed the two back to the table.

Jocelyn stepped back to allow Harry entry and the man followed them to her office. Luke closed the door behind them and turned to face Harry.

"What did you do?" Jocelyn questioned, turning to look at Harry again as the kids left back through the hallway.

"Valentine's dead."

Luke started, rocked back on his heels.

Jocelyn stared at Harry, crossed her arms. "That's common knowledge within the Clave."

"So they didn't know that Valentine was still alive? I saw him just a few hours ago," Harry spoke, his hands loosely at his side. "I killed him an hour ago."

"You're not even a Shadowhunter," Luke remarked, taking another deep breath. "You're not a warlock. What are you?"

"Wizard. What are you?"

"Werewolf."

Harry's lips twitched up into a small grin. "My godfather's husband was a werewolf. I'm okay with it. What's up with the demon blood here? I just arrived on this planet a few hours ago and have no idea what's what."

"You arrived?" Jocelyn asked, raising an eyebrow. "What is that supposed to mean?"

"It means exactly that. I traveled here from another world. What's a Shadowhunter?"

"A Shadowhunter is a person, man or woman, who fights against demons that come here from another dimension or from hell. I used to be one before I was turned," Luke explained. "Shadowhunters have angel blood in them."

Harry's eyes widened a little before he let out a noise of consideration. "Mind if I buy the house next to yours? Jonathan is your son."

"I want nothing to do with him."

"Jocelyn… I have demon blood in me. He'll be fine if he grows up with us," Luke commented, shrugging when Jocelyn turned to him. "Why did you kill Valentine?"

"Child abuse," Harry offered. "I can't stand it. And I read his thoughts. They weren't pleasant."

"You read his thoughts?" Jocelyn repeated, freezing a little.

"A spell."

"You are like a warlock then. Spells and charms… I can't smell any demon blood in you though."

"There are no demons where I'm from." Harry looked between the two of them, eyed Jocelyn with no small amount of apprehension. "Look, I can buy the house next to yours and you don't have to see either of us again. The boy will need a stable childhood, or at least, for his teenage years, and I need people who know how this whole… thing works."

At that, Harry spread his hands out, clearly indicating the world in which Shadowhunters, downworlders and mundanes lived in.

"Besides, I make a very good babysitter."