Clary drove the sword into Sebastian's chest, feeling his bones snap, feeling the blade push through skin and muscle. She was horrified at what she was doing and for a dizzying moment her vision clouded.

His eyes widened and she could see them so clearly, black holes trying to drown her in their emptiness.

"Clary," he gasped, his voice raspy. He gripped the hilt of Heosphoros and wrenched it from his body, splattering her with blackish blood.

His knees buckled, sending him pitching backward. The sword clattered to the ground, spinning out of reach. His limbs jerked and twitched.

Clary watched with a kind of horrified fascination, disgusted but unable to avert her eyes.

He had bragged about being invincible, but here he was, dying before her, a gaping hole in his chest.

Clary fell to her knees, tears of shock and horror sliding down her face, splashing down on her hands. She ignored them as she sat beside her brother, gazing into his eyes.

There was a spark of light in his wound, brightening until it was a flame, licking at his clothes, spreading until it coated him in its fiery embrace. She could feel the heat of the heavenly fire washing over her, but she didn't move. She stared, transfixed, as Sebastian lit up like a beacon.

Jocelyn ran over and knelt next to her daughter. Clary didn't bother looking over to see the expression on her mother's face.

"What's happening to him?" her mother murmured, her voice etched with amazement.

Clary shook her head, a single strand of crimson hair falling into her eyes. "I transferred the heavenly fire that was in Jace to the sword. And now it's killing him."

She heard her mother's gasp but ignored it. There was nothing they could do. Stabbing Sebastian had been the plan all along. It was what had to be done. But why did she feel so torn up inside?

As soon as the flames had started, they disappeared, funneling back into the wound in his chest. His ceremonial red robes were blackened and charred.

"Clary," he whispered.

Clary's eyes found his and an iron fist clutched her stomach. His eyes, once jet-black, were changing. An explosion of color lit his irises, spreading until his eyes were a clear, emerald green. And his skin…his skin was darkening slightly, making him look more human. His face was altering as well, the sharp angles softening, the cruel twist of his lips subsiding.

"I don't understand," whispered Clary. She leaned forward and looked closely at the wound in his chest. The torn skin was slowly knitting back together, mending itself.

Sebastian found Clary's limp hand and he clutched it, his grip surprisingly strong for someone that was supposed to be dying.

"Heaven made a mistake," he murmured.

This is it, she thought. He was losing his mind. Why couldn't he just die already and let her be? She didn't know if she could stand much more of this. She closed her eyes, her lashes brushing her cheeks.

Sebastian's hand was warm in hers. How odd. Weren't people supposed to grow cold as the life left them?

Clary heard her mother's sharp intake of breath beside her. Her eyes opened of their own accord.

Sebastian was sitting up, a look of amazement on his face. His eyes were startling green against his gently tanned skin, lined in curling black lashes. His hair had eased from white to the palest blond, and it stuck up from every angle, ruffled and askew.

He reached forward and brushed the strand of hair from Clary's face. His touch was gentle, sending shivers racing across her skin.

"I don't understand," said Clary, her heart beating painfully against her ribs. Her first thought was that this was bad. Very, very bad. The heavenly fire was her only plan, the only way she knew of that could destroy Sebastian. To put an end to this madness. But it hadn't worked.

And yet…

He was different. This was undeniable. It wasn't just his appearance, but his whole aura. Before, hatred and insanity had encased him. Now, he was a different person entirely.

She could hear murmurs from behind her, growing steadily in volume. The Endarkened were getting restless, and she knew it was only moments before they would attack.

Clary watched in amazement as Sebastian stood up, looking regal even in his tattered clothes. He faced the crowd of destroyed Nephilim. Clary turned to see the looks of shock on her friends' faces and the confusion marking the Endarkeneds'.

"Jace, retrieve the Infernal Cup," he said. Even his voice was the different. It had lost all traces of cold indifference.

Jace blinked, stunned, but bent to retrieve the Cup anyway.

"Bring it to me," said Sebastian. His voice wasn't commanding either, simply…pleasant. As if he was asking a simple favor from a dear friend.

Jace's eyes darted to Clary's, and with a thrill of fear she found herself nodding slightly. What was she doing? Sebastian was still alive, she had to kill him! If not, everything would be lost.

But she sat still, besides her mother, paralyzed. Jace walked up the stairs to the dais and handed the Cup to Sebastian, looking perplexed by his own actions.

Sebastian held up the Infernal Cup, the light reflecting off its surface. The room was completely and utterly silent, everyone gazing at Sebastian.

It was then that he threw the Cup, arm bending back gracefully, propelling it forward. It fell in slow motion, the entirety of the room entranced in its motion. It hit the ground and shattered, fracturing into a million pieces.

"Master!" screamed Amatis, stumbling forward. "What have you done?"

There was sorrow in his emerald eyes as he watched her stagger, an emotion that shouldn't have been possible for him.

"I'm sorry," he whispered, his voice filled with soul crushing regret. "I'm so sorry."

The Endarkened fell, one by one. Their pained cries filled the air for a moment, infecting the room with misery. And then they were dead, their corpses littering the room. Silence lingered, each person not brave enough to break it.

Clary stood up, facing her brother. She searched his face, trying to determine what had happened within him.

"Heaven made a mistake," he said again, his voice drifting through the silence. "The heavenly fire should have killed me. There wasn't enough good left in me to allow my survival. But somehow, miraculously, I did. The demon blood in me is gone, burned away."

Clary heard her mother gasp and begin sobbing, burying her face in her lap.

This wasn't possible. There was no way that Sebastian should have survived. And yet he was here, standing before her, looking perfectly healthy yet changed.

He stepped away for a moment and Clary stared forward, stunned, everything she thought she knew crumbling around her.

He returned, clutching Heosphoros in his hand. It was still dripping with blackish blood—his blood.

"No!" screamed someone from below the dais.

Isabelle threw herself in front of Clary, pushing her backwards.

"Stay away from her," she snarled, her whip curling down from her wrist, resting in a deadly spiral on the ground.

Sebastian's emerald eyes widened.

"Why would I kill her?" he said, real, actual surprise occupying his tone. "I was simply going to offer her the blade."

Isabelle turned to Clary. This was obviously not the answer she had been expecting. Clary nodded and stepped forward, a mere few feet away from Sebastian.

He held out the blade and she took it, balancing it in her palm.

Her brother spread his arms. "Kill me."

Clary took a step back, revulsion clutching her. "Why?" she wondered, curiosity dominating her voice.

He looked at her, smiling slightly. This smile was so different. It was warm and full of life.

"Heaven made a mistake, and you must right it," he said, as if stating the obvious. "I did terrible things. You know that. Even though that was a different part of me, a part which is no longer there…it was still me, in a way. I don't deserve to live."

Clary paused, levelling the sword at his heart. She didn't know if she could do it again. Especially not with Sebastian like this, this different person that she didn't know. This person that should have been alive this whole time, but hadn't gotten a chance, thanks to Valentine.

It was in that moment that she realized she couldn't kill him. She couldn't kill this person—her brother. He wasn't Sebastian at all.

"I'm not going to kill you," she said, her voice shaky. She could feel Isabelle tense up beside her, and her mother's sobs subsided at once. She began again, clearing her throat, her voice strong and steady. "I am not going to kill you, Sebastian."

Sebastian stared at her long and hard.

"Clary, I deserve to die," he whispered, sounding slightly uncertain.

"No," she whispered, tears clouding her vision. "You don't. Sebastian, that monster that landed us in that mess, he deserves to die. But you're not him, are you?"

He shook his head slowly, his eyes still fixed on hers.

"No," he said slowly, his voice sad. "I'm Jonathan."

Clary's thoughts were a jumbled mess inside her head, refusing to let her sort them. How was she letting this happen? How could she allow him to live, knowing all the terrible things he had done?

Yet it seemed completely and utterly wrong to kill him now, when he was so different. And she knew he spoke the truth. The demon blood had been burned away by the heavenly fire. The demon blood had carried the evil, pumping it through his heart, controlling him. Without it he was a different person entirely.

He was her brother.