Hi, and thanks for reading my story! I know that it must be confusing with all the new characters, so here is a list:
Carly Theresa Herondale, 17: daughter of Clary and Jace
Aloise Celine Herondale, dead at 17: Carly's twin sister
Blythe Catarina Lightwood, 18: adoptive daughter of Magnus and Alec
Florian William Lightwood, 19: adoptive son of Magnus and Alec
Elwin Max Raphael Lightwood, 10: adoptive son of Magnus and Alec
Elaine Maryse Rebecca Lightwood, 18: daughter of Simon and Isabelle
Ludwig Carstairs, 19: distant relative to Emma Carstairs, and James (Jem) Carstairs
Alexia Fairchild, 19: distant relative to Clary

I hoped that it helped a bit :) This is my first fan fiction ever, and it is also the first story I've ever written in English, so I'm sorry about potential spelling and grammar mistakes. Hope you enjoy it anyway! xoxo, Sharity.

Carly Herondale was sitting on her bed, reading a book when the knock came. She put the book down before letting the person wanting to see her know that they could come in. It was Blythe who entered the room, all dressed in black, and the color matched her long straight hair. The ice blue eyes were surrounded by spider-leg eyelashes. Now she was batting them at Carly.
"Sorry to interrupt you reading, but our guests has arrived.", Blythe said.
"Already?", Carly asked, surprised and a little terrified.
Blythe nodded.
"You might want to put on something else than you pajamas. Just a friendly advise.", Blythe said and left Carly's room. She looked down at her pajamas. It was pink with teddy bears on it. Carly would die if anyone except her parents, Elaine, Blythe and Aloise saw it. But then she realized, Aloise would never see her silly pajamas again, or tease her for it. She would never discuss books or movies with Carly again, never talk about a cute boy, never laugh until she couldn't breathe, never ask Carly about her opinion on an outfit. Aloise was dead, and nothing in the world could ever change that, no matter how much Carly wanted to.
She turned off all of her feelings, a trick she had learnt when she first heard of her sister's death, and walked over to her closet. It didn't matter anymore what she would wear, so she just picked out a black tank top and a pair of black pants. On her feet, she put on black sneakers. She took a quick look in the mirror on the wall. Her long, wavy hair was strawberry blonde, a mix between the color of her father's and her mother's hair. On her pale skin, her many freckles were visible. Her body was small and slender. She looked mostly like Clary, but in som places, like around the mouth, she looked like Jace. Carly wished that she was as gorgeous as her mother or her grandmother. Even Blythe and Elaine are more beautiful than I, Carly thought for herself before looking away from the mirror and leaving her room to greet the guests.

Blythe Lightwood was not excited about having new people living at the Institute. It was her home now, and she didn't want anyone else to invade it. But her father Alec had told her to put on a smile, so she did. She, Florian, Alec, Clary and Jace had been standing in the great hallway, waiting for the guests to arrive, when Clary had asked Blythe to go and get Carly. Blythe didn't want to. Carly had been such a nervous wreck since her sister died, and it made Blythe annoyed. Sure, it would hurt like hell if Florian, Elwin or Alec died, but they were Shadowhunters. Death was a central part of everyday life. They were bound to risk their lives for others, over and over again. Blythe thought that it was honorable that Aloise had died in a battle against demons. She had fought to the very last moment. So had Agnes… It stung when Blythe thought about her ex-girlfriend, a werewolf named Agnes Nightingale, who had been killed a few months ago. They still hadn't found the killer. Blythe swallowed hard, and pushed away every memory of Agnes, deep into her mind and locked it in a box, and buried the key.

When Carly got down to the big hallway, Ludwig Carstairs and his parabatai were shaking hands with Clary, Jace, Florian and Blythe. Alec had offered to take their bags to their rooms, so he was gone. She immediately recognized Ludwig. She blushed when she was how handsome he was. He had light, brown hair in a cute hairstyle and eyes that looked either gray, green or blue, depending on the light. His body was tall and muscular. Carly blushed even more when she saw the adorable freckles on his cheeks and nose, and his charming smile. She remembered her silly childhood crush on him, and decided to keep her distance, and let her parents handle the talking.
"Ludwig Carstairs? Then you must be related to Emma Carstairs.", Carly heard her mother say.
"Yeah, but very distant related. Do you know her?", Ludwig's voice was soft.
Carly's mother smiled.
"Yes, indeed. She is very dear to me.", Clary said.
Jace, who had been quiet the entire time, turned to girl standing behind Ludwig, his parabatai. She was really cute, with curly, red hair, blue eyes, pale skin and freckles all over her face and bare arms.
"You're Alexia, right? What's your last name?", Jace asked kindly.
"Uhm… Fairchild.", Alexia answered, looking shyly at Jace.
He looked surprised, and turned to his wife.
"Then you're a part of the family. I was born a Fairchild.", Clary said, looking really delighted with the information. Then she must have thought of something else, because the look on her face went dark.
"I'm really sorry for your loss. Just know you are truly welcomed here.", Clary said to Alexia and Ludwig. The latter looked down on his feet. It was Alexia who spoke next.
"Thank you. We are sorry for your loss, too."
The room went quiet. Florian and Blythe exchanged a look. Carly noticed how badly they wanted to get away from all the silent sadness in the room. She decided to spare them further awkwardness, so she headed toward Ludwig and Alexia, discreetly wiping off the sweat on her palms. When he heard her walking, Ludwig looked up on her. She couldn't quite read his what his eyes said, but for a short second, he looked astounded. But why would he be that?
Blythe had also heard her coming, and casually put a hand on Carly's shoulder.
"This is Carly.", she said to Alexia and Ludwig.
Alexia smiled at Carly, a smile that made her instantly like the new girl. Ludwig did not smile.
"Yeah, I know.", he said.
He must have seen the confused look on everyone's faces, because he quickly added:
"We met a few years ago in Idris, remember?", he explained.
Carly simply nodded.
"Okay, sorry, but Clary and I have to go. There have been a few incidents we have to take care of.", Jace said.
"What kind of incidents?", Florian, who had been silent all along, said.
"Murdered Downworlders. Faeries mostly. We don't know who is killing them.", Clary answered.
Blythe looked at Jace and Clary angrily.
"Why didn't anyone tell us?", she asked.
But neither Clary nor Jace got a chance to respond to that, because in that moment, little Elwin rushed into the hallway. He took a quick look at Alexia and Ludwig, but didn't acknowledge them anymore than that.
"Guess who just called me!", he yelled.
Both Blythe and Florian sighed and rolled their eyes at their younger brother.
"Who?", Carly asked.
"It was Father!", Elwin squealed.
Everyone looked confused.
"But… Alec is just in th-", Jace started.
"Not Alec. Magnus! He is back in New York!", Elwin laughed.
Then he turned and ran back the way he came, shouting something about finally see his Father again, and leaving everyone in shock.

Magnus Lightwood-Bane walked the streets of New York City. He had silver highlights in his hair, glitter around his eyes, and he was wearing a suit of sequins. People looked at him funny, or rolled their eyes, but Magnus knew how fabulous he was. At least on the outside. Inside, his soul ached for his beautiful children. And for Alexander, the stunning Alexander Lightwood.
Behold, New York City, Magnus Lightwood-Bane is back, he thought for himself as he made his way to his old apartment in Brooklyn.