Hello people who are reading this. I came up with this story while sitting at my desk (which I'm sitting at right now typing this) looking at tumblr. So let me try to explain it…

So basically Tessa is what she (Demon/Shadowhunter) is but when Will saves her, she immediately wants him, but Will already has a girlfriend; Jem's little sister. Tessa is a hateful bastard (don't hate, I love Tessa) who wants to do something to Jem's sis and get Will. And Will doesn't have the pretend curse; he just left because his sister got killed. Everything will still happen but…with a few twists here and there. And did I mention that Tessa can control peoples' minds for about five to ten minutes?

I just came up with this story for fun so…enjoy! And I am not Cassie so...Fyi: the PoV will be first person in Jem's sister's and Third in Tessa's and will switch between Tessa and Jem's sister.

Tessa PoV:

Tessa threw a pot at his head. "Ow!", the boy cried, rubbing the back of his head, "Lily will want me back in one piece." He looked at his wrist. "You cut me. It could be fatal." She looked at his blue eyes. "Are you the Magister?"

He examined his wrist further. "What massive blood lost. Death could be imminent." Tessa narrowed her eyes, doubtfully. "ARE YOU THE MAGISTER?" He smiled. "Doesn't that mean 'master' in Latin?" She cast him and odd look. "I suppose."

He looked at her clearly for the first time. He had black curly hair that stuck to his temples and dark blue eyes. Tessa felt a strange felling in her stomach, she wanted him. He was so handsome. "What's your name?" He asked smiling. She was taken aback. "What's my NAME? You come barging in here, nearly scaring me to death, and you ask MY name? What is your name?"

The boy's smile grew wider. "Herondale. William Herondale, but everyone calls me Will." He looked around the room and his eyes fell on the bed. "Do you usually sleep tied to the bed?" A rush of heat came to Tessa's cheeks. "No." He frowned. "Oh." Then he-Will-looked to the door. "Let's get out of here, shall we?

Later:

"Do you know what the Dark Sisters had planned for the evening?" Will asked as he traveled down the stairs. Tessa had noticed things about him. He had beautiful blue eyes and a lean face and body. His arms were muscular and his fingers long. Tessa ached for those fingers to be laced through mine. Tessa scolded herself. She shouldn't want a man she just met. But he was so beautiful, charming, and handsome. She shook my head at the question. "No."

Will nodded. "But you were expecting someone called the Magister?" Tessa nodded. "Who's Lily?" Will was caught off guard. Tessa noticed his expression and exhaled. "You said her name in my room. Something about wanting you back in one piece." Will nodded.

"Yes, well, she is…um…a dear…no…I can't describe what's between us, Miss. Gray. Now please hand me the witchlight." After seeing Tessa's confusion, he sighed. "The stone. Hand me the stone." They went on walking and Will headed straight for the Dark sister's chambers. Tessa grabbed a hold of his arm. "NO! Not that way." Will chuckled. "Ah, thank you." Tessa had to let go of his arm.

Later…again.

"Will, she bit me!" The man held his bleeding hand to his chest. He had a kind face. I almost felt guilty for biting him. Will laughed. "Did she, Henry?" Will kept laughing. "We should go." The man whom Will had called Henry pointed at something. "WILL! LOOK OUT!" Will turned to see Mrs. Black advancing towards them. "Damn. I thought I put that thing down."

The woman lunged and ran towards Will. "Uriel!" he pulled something from his belt and cut it through the air. Mrs. Blacks head came clean off. "NO!" Mrs. Dark cried. She advanced on Will and I. She shot lighting from her whole body.

Will lunged for her, shouting at Henry to get me to safety. Henry ran towards me and shielded me from the light. But still the light hit me and I was flung into a wall and could do nothing as the world faded away.

Lily's PoV:

I was sitting at my vanity brushing out my long black locks listening for the soft sound of my brother, James, playing the violin in the next room over, but he would not be playing, he was too ill at the moment. I looked into the mirror. I had a sharp yet soft jaw, big brown eyes, a medium skin tone, and full lips that were always a pink color. I didn't agree but everyone thought I was pretty, especially my brother's parabatai.

I continued brushing my hair out and then put the brush down and went over behind the screen. As I reached to my back to try to undo my dress, Sophie came in. "Ah, Sophie, can you help me with this darn dress?"

"Miss, I don't think you would want to do that. Will and Henry just got back." I started walking to the door. "Thank you, Sophie. And when I get ready to sleep would you please help me undo this blasted dress?" She nodded and curtsied. "Yes, Miss." She went to walk away. "Ah, Sophie, how many times have I told you to call me Lily?" She turned back around and smiled. "Sorry, Lily." I turned around and knocked on Jem's door.

"Come in." I stuck my head in. "Will's back. Just thought you ought to know." My brother smiled from his bed. "Tell him to visit." I nodded and walked down the stairs I found Charlotte in her study. "Where is Will?"

She looked up from the book she was reading. "In the infirmary, he was pretty bad off. The girl he went to get, also, is there. Her name is Tessa." I swiftly walked to the infirmary and saw a girl with smooth, thick, wavy brown hair, an oval face, and a slender body. She looked considerably taller than I was. She was unconscious.

I then saw Will lying in the next bed, unconscious as well. He had burns fading. I also noted that there were many iratze on his skin. "By the angle.", I whispered. I felt myself stiffen. "It's okay, Lily. Will Herondale will be fine." I told myself. Agatha was tending to him.

I turned from the sight and walked back to the stairs and let myself into Jem's room. "Jem?" My brother is quite pale and has odd bright silver colored hair, like an untarnished shilling. His eyes are the same silver, and he has my angular face, with a slight curve of his eyes. He was also tall, very slender and handsome too. He was seventeen, one year older then I.

I came and sat beside him on his bed and take his hand. "Hello, Lily." His eyes open. "Do you want anything?" He sighs. "How's Will?" I look down. "He's unconscious. But his burns are fading." Jem's eyes fly open. "Burns?" I've upset him.

"Calm down, Jem. He's fine. He has iratzes." My brother relaxed a little. We talked more into the night until I said I needed to go. "Goodnight, Jem." I called as I shut the door.

I turned and called for Sophie. She came walking around the corner. "Yes, Miss. Lily?" At least she called me Lily. "I would like you to help me prepare for bed."

Sophie always thought that I was funny, not being able to get out of my dresses by myself. She unlaced the dress and I let it fall to the floor. In my nightgown, I went over to the vanity and unclasped the chain that held my Carstairs ring around my neck. I laid it on the table and rubbed my temples. I received yet another headache.

I told Sophie to go get me some tea with honey. It always made my headaches disappear. She arrived a few moments later with my tea and she sat the tray on the nightstand. I thanked her and lounged on the bed.

After my tea was fixed, I leaned back and read a book and drank my tea. I did this for a while until I felt my eyes beginning to close. Soon the world faded away.

I was awakened by someone knocking on my door. I looked out the window to see the sun had risen. "Come in.", I called. Charlotte and the girl-Tessa-walked in. "Good Morning, Lily. This is Miss. Tessa Gray. This, Miss. Gray, is Miss. Lily Carstairs. Lily, would you mind loaning Miss. Gray some dresses?" I stood and grabbed my dressing robe and walked over to my closet.

"Good Morning, Charlotte. And, no, I don't mind. Which ones would you like, Miss. Gray?" The girl's eyes went over my dresses. "Please, call me Tessa. And I will call you Lily." She pulled out a light pink one. "What about this one?" I took it from her. "I would rather not give that one up. It was my mothers." She nodded and went back to searching. I hung the pink one up.

Tessa ended up with three I really didn't like anyway. She left and Sophie came in a few minutes later. "Would you like me to help you dress?" I nodded. "You know I would, but I can't pick out one. Help?" Sophie came over and pulled out one of my mothers.

It was a deep blue with sleeves that reached my elbow with lace sticking out of the end and lining my collar. It was corseted to my waist and then fell to the floor. In the back the skirt was gathered up in different places.

I slipped it over my head and walked to the vanity. Sophie brushed my locks and styled them into an up-do. She used my mother's diamond pens to hold my hair back but a few locks came out and framed my face. I read until dinner that evening.

I clasped my necklace around my neck, slipped on my shoes, and started to walk down to supper. "Lily?" I turned around to see Will existing his room. "Will!" I started to run to him. He lifted me by the waist as I put my hands on his shoulders and spun me around.

When he put me down, his lips crashed into mine. When he pulled away, I was gasping for air. "Will, you scared me half to death yesterday, lying in that hospital bed. It made me sick."

"I'm sorry to have scared you.", he said smiling. I took his arm and let him lead me to the stairs. We walked down the stairs and I sat beside him. Soon Charlotte and Tessa came in. "Will, you remember Miss. Gray?" Will smiled. "My recollection of her is most vivid indeed." I glared at him which made him smile more. I didn't like the way Tessa looked at him. Something about it made me uneasy.

Charlotte went on. "And Jessamine-Jessie, do look up. Jessie this is Miss. Theresa Gray; Miss. Gray, this is Miss. Jessamine Lovelace. And you already know Lily." I smiled.

I looked back at Charlotte. "Charlotte, where is Henry?" Will interceded. "Yes, where's your benighted husband?"

Charlotte sat and motioned for Tessa to sit as well, next to Will. "He is in the workroom. I've sent Thomas to go and get him. Will again asked, "Jem?" I sighed.

Charlotte again had to answer. "Jem is unwell. He's having one of his days." Jessamine smirked. "He is always having one of his days." Tessa looked like she was going to inquire who Jem was but Sophie and Agatha came in with the food. I watched as Tessa bit into a roll and as she stopped as Jessie stared. Jessie, being the person that she is, just had to talk, "I don't believe I've ever seen a warlock eat." She went on about that.

Will, when she was finished, spoke. "We don't know that she's a warlock." Jessie ignored him and asked if it was horrid to be evil and if Tessa had ever met the Devil. Tessa responded. "Would you like to meet him? I can summon him being a Warlock, and all." Will started to laugh and I covered my mouth to help hide my giggles. I could tell I would like Tessa.

Jessie looked like she was going to say something, but was cut off by Charlotte shrieking. "HENRY!" Everyone turned to find Henry on fire. "Sorry I'm late, darling." Charlotte was staring at him. Finally, Will put him out after a very odd conversation.

Later: (After dinner, everyone knows Tessa can change and control minds.)

Will and I walked the corridors of the institute as we did every night. He reached around to my hair and pulled out my clips. My long locks fell down. Will put my clips in his pocket. He always liked my hair down. We soon found Tessa who looked lost.

Will leaned against a door way. He put me in front of him. "Lost?", he asked Tessa in an amused voice. Tessa turned. Will smirked. I took a step closer. "You should let Will and I show you around, so you don't get lost." Tessa narrowed her eyes. Will looped his arm around my waist.

"Of course", he said smiling, "you can simply keep looking around, but I warn you that there are doors you don't want to open." Tessa frowned. "I don't believe you. But I would like for you to show me around, Mr. Herondale. If you promise no tricks." Will promised. He turned him and I around and I took his arm. Tessa followed on the other side. Before we got to the ball room Tessa and I spoke. "Lily, I think you should go rest, you look tired."

I laughed. "I'm never tired. I fight demons, so I can't be tired." Tessa looked shocked, "You fight?" I nodded. "So does Charlotte. Why do you ask? Do I look to dainty?" Tessa shook her head. "No, I just thought you would leave the fighting to the men." Will laughed. "Miss. Gray, I assure you, if you find a demon, you would want Lily there." I blushed and so did Tessa. We continued on with the tour.

After the tour, Will and I dropped Tessa off at her room. We went to the training room after that.

I went behind the screen, but then realized I could not undo my corset. "Will, come here." He walked behind the screen. "Yes?" I turned with my back to him. "Can you undo my laces?" Will's fingers went to my laces. I could feel them shaking. He got all the laces out and I held the top up. "Thank you." I could practically hear him smirking. "Anytime." I blushed but went back to business.

I changed into gear but could not zip up the tunic. I got the zipper halfway up the back. I walked from behind the screen to find Will already throwing knifes. "Will, can you help?"

He turned and I turned so my back was to him. I held my hair out of the way. I felt his warm hands pull the zipper up. His hands lingered at the base of my neck a few moments longer. I released my hair and turned to him. "Shall we train?"

How do you like it? I might not have a lot of Tessa PoV in the beginning because I need to build up Lily's character. So…review and give me your thoughts

~a hunter of artemis here