Disclaimer: I don't own the characters from Cassandra Clare's series the Mortal Instruments. They belong to her, however I do own Agatha. This is a mixture of the books - combining all them to some degree.

Feels Like Home

Chapter 1.

Jonathon 'Jace' Wayland lay awake in his bed, he was thinking back to when he was a child and realised that some parts of his childhood were completely unknown to him. In a way he wanted to know more, but at the same time he didn't there was always a reason that things were hidden. Clarissa 'Clary' Fray was asleep in the room that she had been assigned, which was a few doors down from Jace. Alexander 'Alec' and Isabelle 'Izzy' Lightwood were both awake and asleep in their respective rooms. None of them could sense what was happening just outside of their walls.

Outside the walls a young woman no older than twenty-one stood outside, there was demons attempting to enter into the institute which was on sacred ground, she was there casting runes to deflect them.

'Hodge, I haven't been here in a long time and I know you know who I am,' a message played on Hodge's phone, although the older man was dead his phone was still on in his office.

Alec had decided on going for a walk to clear his head. He was the oldest of the shadow hunter children. He remembered more than what he let on of what happened to Jace, he had been allowed to on the promise that he would never tell anyone. Alec could hear the young woman's voice coming from inside the room.

"I know that voice," Alec thought to himself as he stopped when he came to Hodge's office, he walked over to the large window and looked out. "Aggie?" he stepped away from the window when he saw her standing outside being attacked. He ran to Jace's room and then to Isabelle and Clary, he was slowly beginning to trust the young girl. "Demons, attacking," with that he ran outside and to the gate, opening it and letting the older girl in. "Where have you been Aggie?" Alec questioned as the teens began to fight.

"Around, and now is not the time – go back inside," Agatha 'Aggie' Wayland said as she pulled a witchlight out of the back of her pants. Like Jace, her last name had been changed when she was little but she still remembered her birth-name.

After a few minutes Aggie had managed to get the downworlders and demons to stop attacking the institute and had made her way inside, where she was greeted not so kindly by Maryse Lightwood. The three teenagers – Izzy, Jace and Clary watched warily as Alec hugged the older girl. It was one of the first signs of affection the older teen had shown anyone.

"Look, I know that I told you a long time ago that I wouldn't return, but there was something nagging at me. Aunt Maryse, please tell me that you've looked after Jace?" Aggie turned to Maryse as she spoke, Alec hadn't let go of her yet – he almost didn't want to. "Alec, I do need to breathe you know,"

"Oh...sorry..."Alec reluctantly let go, Izzy looked at her brother curiously, she wasn't sure who the older girl was and why her brother seemed so attached to her. "Jace is fine, stubborn."

"You haven't told him have you?" Aggie questioned, she wanted to get back to the task at hand but also needed to know just what Jace had been told.

"I haven't and you need to know something else..." Alec muttered the last part of his sentence.

"Jace, hold out your arm. I'd like to do something," Aggie said smiling gently at the younger boy and looking to Alec, Izzy and Clary. "My name is Agatha – but everyone calls me Aggie," she smiled at them as she pulled out her stele. Jace held out his arm to her, he wasn't sure exactly why he was doing it. A few seconds later Aggie drew two small runes on the inside of Jace's arm – one for remember/recall and one that he didn't recognise. "Alec you may want to stand close to him for just a moment,"

"What did you just do? What runes are they?" Clary asked, she was curious as to what was happening and had stepped closer to Jace in order to see. "I know that one being 'remember' but what's this one?"

"You're right the first is remember/recall, but the second is newly created it means family and past...it only really works when..." Aggie paused, there was something about Clary. "Sorry, but what was your name?"

"Her name is Clarissa Fairchild," Maryse told her, the older woman thought about telling that she was Jace's sister – but thought more of it. "She's Valentine and Jocelyn's daughter,"

Jace started to pale as the runes that Aggie had drawn started to take effect. Alec steadied his brother as he started to sway. Aggie stayed where she was, she needed Jace to concentrate on her. Izzy and Clary stared at the three of them, as Maryse moved between the two teenage girls.

"Take a deep breath Jace, and relax," this time it was Alec telling him what to do. "She knows what she's doing," Jace tried to relax and do what Alec told him but it was hard, he was slightly scared but didn't want to show.

"Clary asked what the second rune I drew was, Aunt Maryse would you tell her?" Aggie questioned watching as Alec guided Jace over to the nearest couch.

"The second rune means family," Maryse told her, she knew that Clary didn't have much knowledge of the runes at all. In fact she was surprised that she even knew the rune for remember. "One that was told to Aggie and only Aggie long ago,"

Aggie stood outside the manor house, crouched down in front of her younger brother Jace and his best-friend Alec.'Jace, I have to go away for a little while. But I'll be back when you need me the most,' a then thirteen year old Aggie had said to a then 8 year old Jace before she had turned to Alec. 'Look after my little brother for me,' Alec had just turned 10 years old – he nodded he knew that it must have been important.

'Why do you have to go away Aggie?' Jace had questioned wrapping his arms tightly around her neck. 'I don't want you to go!'

'Because I need to go away to study. I won't be far...' Aggie had replied reciprocating his hug before pulling away from him. 'If you go to your room there's a surprise waiting for you,' she had told him, but hadn't specified what it was. 'Alec I need you to promise me something. You need to look after Jace. I've told your mother – well requested it, that she have someone temporarily erase me from Jace and Izzy's memories...' Jace had come running back outside laughing – his sister had drawn him a picture of one of their pets. 'That's your birthday present, since you will be 9 years old soon,'

After the rune's effects had worn off Jace, Alec looked curiously at him – wanting to know what his brother had remembered. Maryse took Izzy by the hand and pulled out her own stele and drew similar runes on her daughter's arm.

"Jace, don't say anything just take it in. I need to talk to Aggie," Alec grabbed Aggie by the arm and dragged her out of the room.

"What is it Alec?" Aggie questioned, although she had her own questions.

"Jace...he thinks that Clary is his sister...we all do..." Alec said, he was uncertain of what her reaction would be.

"What do you mean Clary is his sister...?" Aggie looked at Alec raising her eyebrow as she spoke and ran a hand through her blonde hair. "There was only me and him...Alec it was always Jace and I..."

"I know...I remember, and that's why I'm so confused about this whole thing. What did Jace see?" Alec questioned, before Aggie could answer him Jace had appeared beside them and was glaring at her.

"Why did you leave me? I was eight years old!" Jace almost screamed at her, his fist clenched beside him.

"Jace, I had to. I may have been thirteen years old but there was things that I needed to do, that I couldn't do in Idris...I went to the institute in New York to talk to the Lightwoods, I knew that if anything happened to dad or you that they would take care of you," Aggie told him, she was trying to think of the best way to explain it to him. "The safest way for that to happen was to have you forget about me...for Izzy to forget, I knew if Alec knew he'd protect you and that's what he's done. I know you hate me..."

"I don't hate you...I just don't know you like I want to," Jace told her, slightly relaxing as he listened to what she had told him. "Where did you go?"

"Around a lot of places, I lived at the institute in London – went back to Idris a few times. I'm sorry I wasn't there when he died," Aggie didn't want to tell him that there father had died long before Jace was ten, or that the Inquisitor was their grandmother. "I'm not going anywhere again," within seconds Jace had wrapped his arms around her, those were the words that he had wanted to hear.