A/N: I just started this one because I got inspiration. Yeah, I have four other stories in progress but still. When inspiration strikes, the only way to get rid of it is to use it. This will take place over a few years. Also: Jonathan is older than Clary by 2 years, & Jace is older than Clary by a year. Enjoy.

JPOV: (Jonathan- 3 Years old *he's well educated okay?*)

As soon as I hear the horses' hooves, I sneak out my window. I'm used to Father going to see Angel Boy but he's been leaving every night. Every night. When he goes to see Angel Boy, it's only for 3 days. But now, I think it's something different. I'm going to find out somehow. I know I will.

1 Week Later...

Father comes home at midnight. At least I believe it's midnight. He looks weary and he carries a little bundle with him. He glances at the bundle then back at me. He sighs. He gestures that I follow him. We walk into an empty room. Or what used to be an empty room. It now has childish things like toys and bottles for babies. Wait... could that bundle be a child. Great! He has another child to take care of! No more attention for me! He already has Angel Boy and me. Why does he need someone else?

Father sits in a rocking chair. I sit on the floor. "Jonathan, this is your sister Clarissa. Your biological sister. Your mother died last week. So, I've been taking care of Clarissa. But, I've decided, instead of traveling, I'll keep her here. If any harm bestows upon her, it will be all your fault. Understand?" He asks. I look into his eyes, "Yes, Father. I'll protect my sister forever. Even if I have to burn down the world to do so." He seems pleased with my answer and sends me to bed. I have trouble sleeping. I have a sister. A real, biological sister. And now I have something I can call mine.

7 Years Later...

JPOV: (Jace- 9 Years Old)

Father hasn't been home for about a week. I know he travels often but he doesn't usually stay a week. He expects me to stay up to date with my studies and training but without instructions or a note at least, I have no clue what I'm supposed to be doing. Since Father has been gone, I have sat in the library each day, reading in different languages all about Shadowhunters and a variety of weapons. I hope he returns home soon. He can be strict but he's my father.

JPOV: (Jonathan- 10 years old)

Father has decided to stay home for awhile. He promised Clary that he would. Today is Clary's 8th birthday. Father told her he would do anything she asked. She had one request- That he stay home for a week. He's having trouble fulfilling the promise but he's staying like he said. He gets nervous and a tad bit anxious. But today is the last day of the week and he will be leaving to tend to Angel Boy again. Clary doesn't know about him yet. She has to wait one more year before we tell her about Angel Boy, her angel blood, and my demon blood. Father doesn't want to pressure her. He thinks that if she has to absorb all of this right now, she will faint or something similar.

Clary and I have been inseperable since Father brought her here. The only times you find us seperate from each other are when we're in the bathroom. But we're still close then, because we're always outside the door. We have seperate rooms but they're adjoining. I usually sneak into her room at night. Sometimes she sneaks into mine after Father has lashed out at me. I've done as Father asked all those years ago. I have protected my baby sister and I will continue to do that. She and I are too close to be seperated. One cannot live without the other.

8 Years Later...

CPOV: (Clary- 16 years old)

I watch in amazement as Jonathan climbs up the house then jumps off of it, landing on his feet like he just jumped down from a horse. He's so lucky he can stand all that. Landing so hard must be painful. Well, to me it would be. I know all about my brother's demon blood and about my angel blood. And I know about Angel Boy, as Jon calls him. Apparently, Father made him think he was murdered infront of him, with Pangborn and Blackwell's help no doubt, and he was sent to the Institute in New York. Father has planned a mission and told us to hurry. Jonathan wanted to show me his new trick first. Older brothers.

As soon as his feet touch the ground, we race to the library. Jonathan is ahead of me by a yard but I pretend to fall. Okay, so I actually fall. But I do pretend to twist my ankle. No, I don't actually twist it. This time I am pretending. As soon as I pretend to whimper in pain, my brother is right by me. "Aw, I'm sorry, Clary. I should've slowed down so you could catch up. Come on, I'll carry you." He picks me up bridal style and I smile inwardly. Naive, demonic, older brother.

He carries me all the way back to the library. Well, for a more appropriate term, he runs while holding me the whole way there. Right outside the library he stops. "Clary, I knew you were faking. But, I love my baby sis too much. I had to carry you. Or you would've lagged behind and Dad would not be happy. You shouldn't be punished for being slow." He whispers in my ear. I hit him lightly on his chest with one hand. He sets me down and we into the library. It still amazes me how many books we have and how few we can touch.

Dad is sitting in his desk in the back. We sit in the chairs facing him. "Clarissa, Jonathan, I have a new mission for you two. A very important mission. I want you two to risk everything and pretend to be a Shadowhunter couple who are lost. You both have a slight accent from going up on the outskirts of Idris and Clarissa can create new runes so you both can speak telepathically. You would need to be careful because I'm sending you to the New York Institute. I need to know if they're plotting against me and I need to know if Jace is still alive. He is still an experiment and I need to know he hasn't killed himself yet. How does that sound?" I look at Jonathan in shock. He looks tense and shocked. Well, mostly pissed off but slightly shocked. I mean, hello, we are biological siblings! By the Angel, all of this is going to come back and bite Dad in the ass one day.

"But Father, we're biological siblings! And you very well know that we can already speak telepathically, you made sure of that. And why do you need us to make sure they're not plotting against you? You've never had trouble knowing before." I exclaim. He nods his head solemnly as if he expected this reaction from me. He probably did. "Most of my men have either fled, died, or can be recognized. And yes, you used to be able to communicate telepathically but can you still?" He waits for us to answer. We nod our heads. We did last week. He continues. "And yes, you are biological siblings. But, Jonathan has Greater Demon blood coursing through his veins along with Shadowhunter blood. You, Clarissa, have angel blood. And the blood is from an angel of rather high stature. So, your blood calls to each other. Plus, we are not mundanes. We do not pertain to their laws. So, let it go. You will have to act like an actual couple. I will know if you are not fulfilling my plans. You are dismissed to pack. Be back within the hour." He waves us away.

We walk out the library and head to our rooms. I just walk through Jonathan's since his door is closer to the library. If you look at our rooms you can see that they're huge. After I pack everything I need, I grab the things I want. The simple things. The art set Jonathan got me last year, the journal I keep, and the family ring. I know I will have to hide the ring but it can't hurt to keep it.

I meet up with Jon in the corridor. He doesn't seem too pleased. "Jon, I know this is going to be weird and difficult and crazy, but Father is hopefully doing this for the best. Hopefully, he hasn't gone too mad." I say, pondering my father's insanity. Jonathan chuckles. I'm usually the only person who can get him to laugh. We go to the library and meet up with Father who already has a portal set up. "Now, remember, I have ways to know if everything is going well. Jonathan, stay by her side, act like you're in love, and don't lose your temper. Clarissa, stay by your brother, act like you're a young couple in love and happy, and don't say anything you shouldn't. And lie about your last names. Use the name Fairchild. Goodbye. I'll send a letter within a week. Hodge is there so he'll give it to you." Father says. He waves his arm to the portal. We step through, holding hands. We land on the ground outside the tall chapel, unscathed.

JPOV: (Jonathan)

I'm going to kill him one of these days. He gave me something of my own and now he's making us act like we're in love and he's driving her away. Stupid Father. I think he has finally lost all sanity. But, maybe Clary will love me. I know I love her. She's the only thing that makes me happy. She's my Clary. Mine.

CPOV: (Clary)

Jonathan keeps a hold on my hand and we approach the Institute. Jonathan has Greater Demon blood and I'm worried about how this will affect him. We've never set foot in an Institute. We've only read about them in our studies. We slowly step onto the steps. Nothing happens. We open the door and enter. Neither of us are being struck by lightning. Nothing bad. We continue on until we find an elevator. It's ancient but beautiful. It seems like something I would like to paint. As the elevator goes upward, I face my brother. I'm so nervous. "Jon, I'm scared. Dad has had crazy suggestions before but this is the craziest. Hell, I've never even kissed anyone. I'm scared about us having to pretend to be a couple and I'm scared that they'll find us out." I whisper. Jon comes over to me and holds me close. He hums low in my ear.

It'll be alright, Angel Girl.

I hope you're right, Demon Boy.

He assures me telepathically. I nod my head at him. He releases me but holds onto my hand again. I squeeze his hand tightly as the elevator stops. We step onto the floor and we head toward noise. There are several voices. Maybe six or seven voices. Both male and female. We stop at a door down a long hall. The voices stop as well. Jonathan knocks on the door. A tall, black haired, dark eyed girl opens the door. She looks at us with narrowed eyes then sees our runes. She looks behind her. "Mom, there are some Shadowhunters here." She opens the door for us. We follow her into the library. She leads us to the back where six other people are. There is Hodge. We've met him before. There is a really young brown haired boy with blue eyes and glasses. There is a tall, black haired, blue eyed boy and a woman and man who look similar. Then there is a boy who is completely golden. He has golden hair, tanned skin, and his eyes are golden too. And looking right at me. Angel Boy smirks at me. "Checking me out, redhead? Don't be ashamed. Everyone checks me out." He says with so much arrogance.

Jonathan pulls me closer and we both glare at him. The older woman approaches us with the man. They must run the Institute. "I'm Maryse Lightwood and this is my husband, Robert." She says. I smile. "I'm Clarissa. This is Jonathan." I tell her pleasantly. She smiles back. "Hodge is our tutor and friend. These are my children. Max is the youngest. Isabelle is over there," she points to the similar looking girl. "And these are my sons. Alec is the eldest. Jace is our adopted son but we don't dwell on that." She points at the two boys. "I'm sorry, but I didn't catch your last names." Robert says once his wife is done speaking. "I'm Jonathan Herondale. This is my girlfriend, Clarissa Fairchild." Jon says. I'm taken aback by the name he chooses as a last name. I know that that is actually Jace's last name. But, I guess it's the first thing he could come up with.

Hodge seems a little surprised too but he quickly acts normal. The Lightwood parents seem surprised though. "Well, Jonathan, you do look like Celine. I'm sorry to hear of her death when you were young. And Clarissa, you are the spitting image of your mother. I'm sorry to hear of Jocelyn's death. Where have you been before now?" Maryse asks us kindly, sympathy lacing her voice. "Well, we were both in London before now. We grew up in the Institute there. But we decided to come to New York and we didn't think ahead, so we don't have anywhere to stay. Well, we did but we got a call saying they were giving away the apartment for a better price. So, now, we're lost." I say trying to act sad.

Jonathan squeezes my shoulder. "You can stay here while you're in New York. And it doesn't matter how long that is. We could use with some new Shadowhunters around here." Robert says. We thank them. The children don't seem to like us. Maryse shows me to a room and just as she's about to show Jonathan his own room, I protest. "Um, Maryse, would you care if we shared a room? We've always been together and I often have nightmares when I'm without him. Jonathan is all I have." I try to put so much love into that one statement. She looks between us then at the room. She sighs. "Alright. But no sex." Then she walks away. I smile at Jonathan. We go into the room and put stuff up then I start laughing. Jonathan looks at me then starts tickling me, making me laugh harder. He eventually stops tickling me when I beg and plead. He can be a good brother sometimes. Well, most of the time. But he's mine. My brother. Mine.

A/N: Sooo... what are you thinking? Did you like it? Did you hate it? What do you think will happen next? Tell me. Review.

~Lila Belle