Disclaimer: I do not own The 100. Any similarity in storyline or dialogue originated with the show or book.
Summary: "Bellamy Blake's one weakness is his sister. There's just something a little off about her." What would change if Bellamy had a sister that never had to live under the floorboards? Madeleine Blake goes to Earth with the 100 and Bellamy follows her down, but she doesn't integrate with the 100 as well as her brother.
A/N: My OC's face claim is Melissa Benoist. Ideas for other face-claims are welcomed. Octavia Blake does not exist in this story. Please give me some feedback in a review and favorite and follow. Enjoy!

Heaven and Hell

Rejected. That was how Madeleine Blake had felt since she was a child. And it wasn't because she was a second child in a place where they rarely existed. It was because there was simply something wrong with her—something unpleasant. Madeleine never figured out what it was. All she knew is that people tended to stay away from her. She realized there was something repulsive about her the day her mother gave her up to the orphanage. Madeleine had never been looked at with love or kindness by anyone, including the woman who gave birth to her. It was always rejection and hostility. Madeleine never really understood it, but those moments shaped her into the woman she became. There were worse things to happen to her since her mother gave her up, but without it things would have turned out very differently.

People often thought Madeleine to be stupid or retarded, but truthfully she was highly intelligent and gifted at reading people. In the orphanage she had picked up the habit of only speaking when she had something to say. Instead, she would listen, observe, and store information for future use. That process was a lot more useful than spending her time talking. But she never corrected anyone when they called her stupid or retarded, and she never made the attempt to prove them wrong. There was never any fun in that.

Madeleine's first positive memory was of her brother, Bellamy. While their mother never wished for them to be close, he had always found a way to come and see her. She had immediately recognized the connection they had. They bonded almost instantly. After that she sought his approval, affection, and sometimes even his protection. She would do anything for him and he would do anything for her. Some of the other kids in the orphanage had mocked Madeleine because of her closeness with her brother, called her names, but it never meant anything to her.

Bellamy had rewarded her devotion with love and care and the promise of someday getting her out of the orphanage. He was the only one to accept Madeleine the way she was and make her feel as if she mattered. She never had to hide her innermost feelings and darkest thoughts with him. He never mocked her or used anything he knew about her against her. It was true, Madeleine could be vicious and unforgiving, and she often took pleasure in things that appeared dark to others. She enjoyed doing things that annoyed people in the weirdest of ways, but Bellamy never cared about that. There were a few people who dared to insult her as she grew older, but what they thought of her made no difference. They didn't truly know her and they didn't want to. She was proud to be who she was.

She was taken from the orphanage when she was fifteen. Bellamy was old enough by that time to legally adopt her. Their mother didn't approve, but neither of them cared about that. They were together and they were happy. Bellamy was working his way up in the Guard. Madeleine on the other hand was enrolled in school and was able to spend the rest of her day with her brother. She never made any friends in school or outside of it, but she did have Bellamy. That was all that mattered to her.

Madeleine had always been gifted at thievery, but when she tried to steal an old baseball jersey for Bellamy's birthday, she was caught and sent to the Skybox. Bellamy never really forgave her for that, but he never held it against her. She was there for a little over a year when they were all rounded up onto a ship and sent down to Earth. She didn't give anyone the satisfaction of crying, but she felt broken on the inside because she had been separated possibly forever from her brother.

It wasn't until they landed that she realized she hadn't.

She didn't get up after the drop ship landed. The kids from their level and the level above were still spilling onto the ground level and Madeleine didn't want to get swept up in the crowd. So, she waited.

But then she heard his voice. It was the voice of her older brother, her best friend, her other half. Bellamy.

That's when she undid her seatbelt and shot out of her chair. Her feet moved at a hurried walk as she made her way to the ladder that led her down to the ground level. It was where she knew the voice of her brother was coming from.

She stopped on the ladder when she saw his dark head of hair standing by the big metal door with his hand on a lever.

"Bellamy?" Her voice came out tiny and her throat felt raw. She hadn't spoken in days.

When he faced her, she continued down the ladder and pushed her small body through the thick crowd of kids standing between her and Bellamy. She could feel their eyes on her, but she didn't care in the slightest. Her focus was on her brother.

"Oh, my god," he said when he finally saw her standing in front of him. "Look how big you are."

She didn't hesitate to throw her arms around his neck and place a short kiss on his cheek.

Madeleine stepped back and looked at her brother. He seemed to read her mind.

"Someone had to keep an eye on you," he said with a smirk.

She went to hug him again.

"Where's your wristband?" A girl asked from behind them.

Madeleine let go of Bellamy and faced the girl, giving her a look that sent most people running.

"You mind?" Bellamy asked. "I haven't seen my sister in over a year."

"Sister?" Someone asked.

"Almost no one has a sister," another person said aloud.

"That's Madeleine Blake," a girl said from somewhere in the back, "the weirdo who was caught stealing a stupid shirt."

Madeleine kept a calm look on her face as she started towards the crowd, but Bellamy could see she meant to cause some harm.

"Hey, hey, hey," Bellamy said. "Let's give them something else to remember you by."

When Madeleine shot him a look he continued, "Like being the first person on the ground in a hundred years."

She smiled and he had his answer.

They turned together towards the door and Bellamy pulled the lever, causing the door to swing open. The brightness blinded them for a moment, but then they saw everything all at once; the trees, the grass, the flowers, the sky, the clouds.

Madeleine breathed in a lungful of air and opened her eyes as she let it out slowly. She stepped forward until she reached the end of the door. The ground was inviting when she looked down so she inhaled and jumped.

"We're back," she said just loud enough for everyone aboard the ship to hear. Madeleine stayed in the same spot as the rest of the kids rushed past her. She didn't move until Bellamy came up beside her. She raked a hand through her messy brown curls and smiled up at her brother. "We're back."

It was her eyes, Bellamy knew. It had always been her eyes. They were the thing that always set people on edge. There was something dark and twisted about the way Madeleine would look at people. It was almost predatory. It was also the way she looked. She always looked untidy with her dark messy curls and clothes that were too big for her small frame.

Madeleine rarely spoke, but she was good at sneaking around and watching people with her icy blue eyes. Their mother had admitted several times that she regretted giving birth to her. She always said there was just something wrong with Madeleine, but Bellamy never regretted reaching out to his sister. He never acknowledged any of the things that made her different to everyone else. To him, she was perfect just the way she was. And Bellamy never forgave his mother for giving Madeleine to the orphanage on the Ark.

But then he got her back. He took her back. And they were happy until the day that Madeleine tried to steal a birthday present for him. Bellamy was angry, but he was also upset. His sister was being taken from him again. It was like an unending cycle.

He broke that cycle the day he followed her down to Earth.

Madeleine was walking beside her brother when they listened in on a conversation. She stayed by her brother's side and vigilantly observed the small group of kids forming a few feet from them.

"We're just trying to figure out where we are," a delinquent said to another group of delinquents.

"We're on the ground," Bellamy said. "That not good enough for you."

"We need to find Mount Weather," the young black man said. Madeleine noticed how the blonde girl followed behind him. "You heard my father's message. That has to be our first priority."

"Screw your father," Bellamy said as Madeleine thought it. Bellamy smiled lightly when the younger man narrowed his eyes. "What? You think you're in charge here?" Bellamy looked at the girl standing beside the delinquent. "You and your little princess?"

"You think we care who's in charge?" The blonde asked. "We need to get to Mount Weather! Not because the Chancellor said so, but because the longer we wait, the hungrier we'll get and the harder this will be. How long do you think we'll last without those supplies?" The girl paused as she looked around the growing crowd. "We're looking at a twenty mile trek, okay? So, if we want to get there before dark, we need to leave, now."

"I got a better idea," Bellamy announced. "Why don't you two go? Find it for us? Let the privilege do the hard work for a change?"

Madeleine smirked when the other kids shouted in agreement.

"You're not listening," the black teen said loudly. "We all need to go!"

Madeleine turned on her heels and walked away through the crowd when a fight broke out. She hated drama more than she hated people.

"I can't stay with them, Mads," Bellamy said when he caught up with her.

She raised an eyebrow.

"I did something, okay? To get on the drop ship," Bellamy explained. "Something they will kill me for when they come down. I can't say what it is just yet, but you have to trust me. You still do trust me, don't you?"

"Of course," Madeleine stated calmly.

"Then we need to leave as soon as possible," Bellamy told his sister with a small smile. She nodded and he pushed a curl out of her face. "I love you, Mads."

"I love you too, Bell," she responded.

Madeleine turned her head when she heard something peculiar. She grabbed Bellamy by the wrist and pulled him along to the small group by the drop ship.

"Can we go now?" A shaggy-haired teen asked the same blonde girl from before. The girl nodded.

"I'll go," Madeleine said just loud enough for the few kids to hear.

"What are you doing?" Bellamy asked as he grabbed her arm.

"Listen," Madeleine mouthed to her brother.

"Hey, were you trying to take this off?" The blonde girl asked as she grabbed the shaggy-haired kid by the wrist. His metal cuff had a long dark line across the side of it.

"Yeah," he said and quirked an eyebrow. "So?"

"So this wristband transmits your vital signs to the Ark," the blonde said. "Take it off and they'll think you're dead."

"Should I care?" The shaggy-haired kid asked. Madeleine pursed her lips to stop herself from smiling. She already knew the answer the blonde was about to give.

"I don't know. Do you want the people you love to think you're dead?" The blonde asked with a raised eyebrow. "Do you want them to follow you down in two months? Because they won't if they think we're dying."

When the shaggy-haired kid stayed quiet, the blonde sighed. "Okay. Now, let's go."

They started walking away, but Madeleine faced her brother and smiled.

"I'm going to go with them and get some supplies for our trip and you are going to stay here and get as many kids as you can to remove their wristbands," Madeleine stated. She stepped up onto her tiptoes and kissed his cheek. She placed her lips by her ear and whispered, "This will work out. I'm not going to lose you again."

Bellamy nodded as she stepped back. "I love you, Mads."

"And I love you, Bell," Madeleine said before following the others into the woods.