Summary: Clary and Sebastian (Jonathan) Morgenstern have a child together-a daughter named Adele. Clary dies shortly after giving birth to her daughter and Sebastian is supposedly killed by Shadowhunters when Adele is a few months old. Taken in by Jace, Isabelle, Alec, Magnus and Simon, Adele grows up in a relatively normal Shadowhunter household. What happens when Sebastien, who isn't really dead, comes after his daughter? And with the discovery of powers she didn't know she was capable of having, powers strong enough to destroy heaven and raise hell, her biological father's new plan to storm the world with his Endarkened Army, as well as resurrect her dead mother, Adele falls right into the middle of the grand scheme of things. Will she turn against her Shadowhunter family, the one that raised her since birth, and join her father? And will she rule by his side as the new queen of hell? The First Part of "What Cannot Be Forgotten" by Amberlily34567.

Disclaimer: I do not own the Mortal Instruments series. This right belongs to Cassandra Clare. However, the story line which I have developed should not be plagiarized or duplicated without my permission. The characters all belong to Cassandra Clare. However, what they do in this story is in my control and I do not appreciate plagiarism. Also, I do not support all the ideas in this story. There may be dark parts later on in the story with sensitive, triggering subjects and I will give warnings in the chapter before and at the beginning of that chapter. If the story disturbs or triggers you in anyway, I suggest you stop reading farther. As of now, this story is rated M for triggering subjects later on and language. Anything that happens in this story is purely fictional and should not be attempted in real life. I am not responsible for injury or anything that happens should someone try anything from my story.

A/N: Welcome to "What Cannot Be Forgotten", a story about Sebastien and Clary's daughter! Yeah, I know incest is bad and I don't recommend it because of all sorts of risky things. However, this story does discuss the topic so if your really young or don't like that kind of stuff, please don't read or skip those parts (I'll give a warning). Anyways, I'll keep this short. Please remember to review and tell me what you think!

Enjoy and Happy Writing!

-Amber

"Adele!"

She jerked awake, nearly falling out of her bed.

"Simon!" She shouted back, annoyed that he had woken up. A moment later, his dark hair poked into her room and he was grinning. Bastard, she thought.

"Jace told me to wake you up,"

"Jace should have done it himself," she muttered, not making any attempt to move from the covers of her bed. New York could get cold very fast, especially upstate and at the point of seasonal change where autumn wasn't really over yet but winter hadn't started either.

Simon scratched his head. "At least I only yelled at you to wake up," he said, "I was calling your name six times before you finally decided to wake you up. Jace would have just dumped a glass of water or started playing drum solos against your head."

Grudgingly, she admitted he had a point. Jace had never been one for patience. He thought that when he was up at the crack of dawn, the rest of the world needed to be awake with him. And if the world decided not to cooperate...cue the start of World War Sleep.

"Where is he, by the way?"

"Out hunting demons with Isabelle," he grinned, "he said if you woke up by six, he'd consider bringing you back something from the bakery."

"How nice of him," she climbed out of bed, "threatening me with starvation if I don't listen to him."

"Not really-I've never seen you listen to him. You'd be dead by now if he actually carried out those threats."

Adele yawned, stretching. She picked up the stele by her bed and started drawing a rune on her hand.

"What are you doing?" Simon asked, looking a bit nervous. She remembered one vague incident when she was twelve in which she had accidentally drawn a wrong stroke on a rune and had set fire to the downstairs bathroom. Cursing profusely, Jace had put out the fire and yelled at her for a solid five minutes before losing steam and passing the responsibility over to a shaken Simon, who had been using the bathroom when she had so conveniently decided to set fire to it. Adele rolled her eyes, smiling.

"Relax; I'm just trying to find Jace's location."

"With a rune?" Simon looked doubtful. "You could just facetime him…"

"Yeah, right," she snorted, "he hates phones. He doesn't even like it when I have mine on me."

Simon frowned but didn't ask further details. Smart. Closing her eyes, she saw a vague hazy image she recognized as Central Park. They must have used a Portal to get there.

"Jace says you have to be ready by 6:15."

Her eyes snapped back open again. "6:15?" She glanced at the clock next to her bed. "But it's 6:10 now!"

Simon shrugged, as if it were no concern to him. "Get dressed."

Muttering about last minute plans, Adele waited until Simon was out of the room before closing the door and pulling of the top she was wearing. It was one of Jace's old shirts; he always seemed to have the best, comfiest shirts, which really wasn't fair. She pulled on another shirt, this one a present from Simon-a Star Wars shirt reference she sort of understood-and leggings. Her hair, which she had washed the night before, decided to become frizzy at the exact wrong time.

"Come on, come on," she muttered as she ran a comb through the strands, only succeeding in making them even more wild and unruly. Her hair was naturally straight, so she couldn't even blame natural causes or genetics. Giving up, she pulled it into a low ponytail and decided she would ask Isabelle to sort out the problem later.

When she went downstairs, it seemed her hopes of beating Jace to the kitchen were dashed. He was standing there with his familiar signature smirk, drinking a cup of coffee and holding something-a cinnamon bun. Her stomach growled in hunger and he knew this to; she met his gaze defiantly.

"Morning," he said. "Hungry?"

"You wish," she said underneath her breath, as she took a seat at the table. Her eyes landed on a white box at the center of the table; pastries, she guessed. Once more, her stomach growled, reminding her of the fact that she had only a sandwich to eat the night before. "I'm assuming demon hunting went well, then?"

"Obviously, by the fact that I'm still alive and talking to you." Jace finished the bun and ripped open the box of pastries. It physically hurt to see him lift a cream pastry from the box and lick some of the icing of his fingers. Sometimes, she wished she wasn't so stubborn. Were they seriously arguing over pastries and wake up times?

"Aren't you hungry?"

For a moment, Adele considered giving in. But then he was smirking at her, as if he knew the battle that was going on between her mind and stomach. Two can play this game.

"No," she replied sweetly. "Where's Isabelle?"

He shrugged. "Making something for lunch. Can't you smell it?"

Actually, she could. Slightly putrid, smelling of something poisonous. She wasn't sure how she missed that. Jace raised his eyebrows at her, waiting her verdict.

"I thought mustard gas was illegal," she finally replied. Jace's mouth quirked up into an amused grin as he chuckled.

"Eat," he said, pushing the box of pastries towards her, "or you'll have to be the guinea pig to whatever new recipe Isabelle's trying out now."

Adele seriously doubted that would even guarantee her safe. Isabelle had been known on occasions to use emotional blackmail to get her to try some new variant of oatmeal she had decided to create. Still, she grabbed a pastry from the box and bit into it. Lemon cream and meringue filled her mouth.

"Thanks," she mumbled through a mouthful. Swallowing, she reached for the coffee pot. "Can I have a mug?"

Jace grabbed a mug from the cupboard above the sink and handed it to her. She poured herself a cup of coffee, black, with no sugar and washed the pastry down with it. There was mail on the table; he ripped open an envelope. There was a black and gold seal on it.

"The Clave?"

Jace frowned as he scanned the letter inside. "Something like that," he muttered, tucking the letter away once more. "Your mom's birthday is on Saturday."

She froze. Jace was being casual about it but she could hear the underlying emotions in his tone of voice.

"That's...nice," she finally said, not knowing what else she could possibly say.

"Yeah," he agreed. He was watching her with a strange, almost unreadable expression on his face.

"What?"

"Nothing," he shook his head. "Just...you remind me of her."

Adele nodded. She was used to people commenting on the resemblance between her and her mother. They had the same freckles, although hers were supposedly fainter and their eyes were bright emerald green, courtesy of the signature Fairchild family line. Even their noses curved up in the same fashion. Except, where her mother's hair had been bright, flaming red, her's was a pale, white blonde, so pale that in the right lighting, it looked like she had snowy white hair.

"What was my mother like?" She asked, even if she had a thousand times before. Jace cleared his throat.

"She was...stubborn, like you. And brave. Very brave. And…"

Adele could see the physical pain as he struggled to get the next words out of his mouth. Before he could say anything, however, she was already out of the chair, wrapping her arms around him. He stiffened, almost as if he was unsure what to do but then he wrapped his arms back around her. He was warm and he smelled like aftershave and something metallic. Blood, maybe. Her own father had died shortly after she had been born and Jace had found her in the nursery. She had been only a couple of months old but he had made the split second decision to save her and take her with him.

Of course, the Clave had objected. They had argued but Jace had been adamant. Isabelle, Alec, Simon and even Magnus had taken sides with him and eventually, they had allowed her to stay, underneath the condition that she be brought to them periodically. Jace had refused to tell her why.

"Did you love her?" She asked, her voice muffled where her head was buried in his shoulder.

She felt him gently stroke her hair. He wasn't normally one to openly show affection, and she had never heard him utter the words "I love you" to anyone. When she was little, she had often wondered if he was even capable of emotions. He reminded her of a machine-eat, sleep, breath, fight, kill. Now that she was older, she understood that he didn't let anyone get too close because he was afraid of losing them. Adele was one of the only who had managed to come close enough to him to hold his heart. It probably helped that she looked so much like her mother, she thought as she waited for his response.

"Yes," he said, "I...loved her."

Adele pulled back as someone entered the kitchen. Simon.

"Sorry, was I interrupting something?"

"Clary's birthday is on Saturday," Jace said, a little bleakly. Simon tensed.

"August 23rd," he said. "I remember."

They both glanced at Adele and it was as if silent understanding passed between the two of them. Simon turned away, grabbing a plate and Jace turned back to Adele.

"I called you down because I wanted to take you somewhere."

"Where?"

"I thought we might go shopping for some clothes."

Adele narrowed her eyes in suspicion. Usually, it was Isabelle who took her shopping. Simon would go if she really persisted in begging him, and Alec and Magnus would only come along to make out in the changing rooms (yes, they were that loud). When she was younger, maybe up till the age of nine or ten years old, she would sometimes put on the clothes they had brought and make Jace sit down. Usually tired and half asleep, he would nod in approval as she modeled clothes, sometimes giving her a thumbs up, other times murmuring a sleepy, "deserves to be on the cover of Vogue and Seventeen." She didn't understand why people found him to be such a cold hearted bastard, quoting one person she had overheard on a visit to the Institute where he was the head of. He was nice. Just not nice in the way most people wanted him to be.

"It'll be fun," he shrugged. "And I need to run some errands as well."

"Isabelle's not coming?"

He glanced at the door which led to the kitchen. There were two kitchens in the house; one of them for eating and storing cutlery and another for actually cooking. It had been a major screw up by the architect who had done it but no one was complaining; it meant that everyone could eat in peace without fear of passing out from Isabelle's experiments in the second kitchen.

"Do you want her to come?" He asked, a little amused.

Adele shook her head. "No," she replied, "let's go."

Jace led the way. "Put on a jacket," he said.

"I don't have one. Mine was destroyed in the demon attack on Tuesday, remember?"

Jace sighed, running a hand through his hair. They both had the blonde hair, although his was a richer gold color then hers and much more fuller. Her own hair was pale and fine, not thick at all like his. Still, if it came to it, they could pass of as cousins.

"Right." He sighed. "Well, just take Alec's, then. It's in the hall closet."

"Won't he mind?"

The familiar smirk made its way known on his face. "I don't think he'll be getting out much. Magnus came to visit today."

Ah. That made sense. Suddenly, she was glad that she was getting out of the house. Alec's room was right next to her, and the walls to the house were thin to the point that she could hear everything going on in their room. Jace and Isabelle had given her the Talk when she was thirteen but she doubted she needed it with Alec and Magnus to educate her.

"Stele?"

"Got it," she waved hers. "What about yours?"

"Always on me," he replied. "I taught you to make a portal, right?"

She nodded. He stepped back as she disappeared into the hall closet, which wasn't really a closet but a closed of room in the house that no one knew what to do with. She stopped, picking up a jacket from the floor she recognized as Alec's. It smelled old and dusty and could easily fit his six foot frame. However, she was 5'5, so she looked utterly ridiculous standing there with the jacket hanging of her.

"Adele?"

"Over here," she called. Waving her stele, she muttered something. For a moment, nothing happen. Then a faint light, growing blue and becoming brighter and brighter by the moment shone through the closet.

"Where are we going?"

"Waterwoods, Ursula's cellar."

She concentrated, trying to capture whatever vague memory she had of Ursula and her cellar. It was big and...dark, and damp. Onions. It smelled like onions and wet rope.

"Done," she said. She offered him her wrist as she pulled him through the portal. There was a tilting sensation as the world seemed to lurch and something cool on her face. Wind whipped past her, throwing her hair into disarray. She really should have braided it.

Suddenly, they stumbled out onto the floor. She nearly tripped over a sack of onions on the floor but Jace's hand shot out to stop her.

"Thanks," she said. He nodded. Her eyes were starting to adjust to the darkness and she could make out onion sacks on the floor. Thousands and thousands of onion sacks.

She heard a door upstairs slam and Jace mutter a curse in French.

"Come on," he said, grabbing her arm. Another door slammed and he managed to push them back behind the stairs before the door to the cellar opened and Ursula came down.

Adele started, unabashedly although she had been told repeatedly that it was rude to do so. She couldn't help it; even Jace was staring. Ursula was a thin woman with arms and legs as long as pool noodles. Unlike pool noodles, however, her arms lacked any color. Her skin was even paler then Simon's and that was saying something; Simon was a vampire, after all.

"Shadowhunters?" Ursula called softly. A warning hand on her forearm from Jace told her not to say anything, although she wouldn't have anyways.

"Shadowhunters? Is someone down here?"

There was a tap tapping noise and Adele felt something like a chill in her blood. Being brought up in a Shadowhunter household with people like Jace and Isabelle to teach her, she had always been told that fear would end her.

"Never be afraid," Jace had told her. "Fear clouds judgement. Fear slows you down. Fear makes you weak."

So Adele forced herself to stay calm.

There was more tap tapping and it was even closer this time. Adele remembered how Ursula was blind. She couldn't remember the exact story behind it but her eyes had apparently been plucked out. The woman couldn't see. Hence, she used the stick to guide her way. In her own personal opinion, Adele thought she should have just gotten a dog, but she knew better then to suggest that.

"Shadowhunters? I heard the portal…"

She drew her stele out of her pocket and handed it to Jace. He knew what to do. Silently, he begun drawing on her skin, the runes burning and hissing as they came in contact with her skin. When he was finished, she felt an odd lightness.

She felt him push the stele into her hands. Ursula was in front of the steps now, coming round the sides, her stick tap tapping the way ahead. Jace moved back an inch and there was a crunch as he stepped on dried onion skin. As if drawn to the noise, Ursula started moving a little faster towards them.

"Hurry," he hissed quietly. Quickly, she drew the rune on the skin of his forearm, the movement familiar and sure and when she looked up, she realized with a jolt that he was semi transparent. Barely visible, and as the seconds ticked on, he kept getting fainter and fainter before she could barely make out his outline anymore.

Ursula was here. Jace gestured at her to follow and quietly, they snuck out from behind the stairs. There were onion skins littering the ground but when she put her foot down, her foot passed right through them, as they were hallucinations.

He pushed her in the direction of the stairs and she moved up the stairs. She was sweating with the effort to keep herself afloat.

"Found you!" Someone cried behind her and there was a loud smack. She nearly fell through the steps.

"Go," Jace hissed in her ear. She moved forward, passing through the slightly open cellar door into the bright light above. When she looked back, she found Jace nowhere to be seen.

"Jace?" She called.

"Shh," he was in front her, gripping his own stele. "Come on, we don't have long before the runes wear of."

They floated through the house. It was eerie how they seemed to have almost no substance, and yet that was exactly what the runes had intended to do. No substance. They were like disembodied particles floating through the air and if they had any form, they might find that one of their arms was behind their head or their legs were turned the wrong way.

They managed to pass through the front door.

"Wait here," he said. The runes were already wearing of. Her body was starting to feel heavy again, and when she looked up, Jace was starting to look normal again. Suddenly, she felt a popping sensation in her ears and she could feel her own solid feet again.

"You good?" Jace asked, looking at her.

"Yeah. What about you? Actual flesh and blood?" She reached out and tugged the sleeve of his shirt. She saw him smirking.

"The real thing," he said, "the one and only Jace Wayland."

"So arrogant," she rolled her eyes, smiling a little.

"How is that a bad thing?"

Adele shrugged half heartedly. "Come on," she said. "Before Ursula drags you back down to the cellar."
He cringed. "You really had to bring that up, didn't you, Adele?"

She laughed, remembering the time when Ursula had caught them and insisted on making tea and cookies for them. Well, mainly for Jace. She had ignored Adele most of the time and kept her attention focused on Jace, grabbing his hand at times and making him nearly spill tea all over the ragged brown carpet. Jace hated tea but Adele loved it The visit ended with a kiss on Jace's cheek. She could never forget the expression on his face at the moment-part "I want to die," part, "If you mention this again I will kill you."

"It was funny," she argued.

He gave her a long look. "I honestly don't get your humor sometimes," he said.

Adele simply smiled up at him, batting her eyes innocently. She had quickly discovered one of Jace's weakness-puppy eyes. No matter how hard he tried to fight it, the eyes always won.

"Don't do that," he scowled, looking away.

"Do what?"

"Never mind," he shook his head. "Let's go. If we hurry, we can be done by lunch."

~:~

I'm back.

The letter wasn't signed.

Simon and Isabelle exchanged nervous glances. Alec picked up the letter.

"This," he said, waving the envelope around, "is going in the trash. Has Jace read it yet?"

Isabelle nodded. "I heard him from the kitchen,"

"Does Adele know?"

"No," Simon shook his head.

Alec tore up the letter, tossing the pieces into the trash.

"It's just a prank,"

"Yeah," replied Isabelle, although there was a concerned expression on her face.

"Definitely," added Simon, sounding like he didn't believe a word Alec had said. Just a prank. Just a prank. Maybe if they repeated the words enough times, they would actually start to believe them. What kind of stupid prank was this? Who would do such a thing?

Alec was the first to break the silence. "I'm going to go see Magnus,"

"Didn't you see him yesterday?"

"Yes, but we didn't get a lot of time together,"

Isabelle snorted but didn't say anything more. There was a faint burning smell coming from the kitchen. She leapt up.

"Oh, damn!" She cried. "My cookies are burning."

Alec sniffed. "You call those cookies?" He muttered cynically. "They smell like Jace's dirty socks."

"Smell a lot of those lately?" Isabelle shot back. Simon knew better to break them apart. The last time he had tried, Isabelle had tried to claw Alec's face and ended up clawing Simon's instead.

"Whatever," said Alec. "I'm going."

Isabelle watched him leave. "Boys," she said, underneath her breath, heading towards the kitchen to salvage her cookies.

~:~