The red lightsaber sang with joy as its master watered it with innocent blood. The children fell like dolls, just so much dead weight after the weapon had cut them clean through. Behind the boy who was once so loved and welcome in these halls came the Knights, shooting every Padawan their leader missed.

Kylo Ren's eyes were dark behind his mask, gleaming with grim excitement, because he was doing this, really doing it, and as his sword cleanly beheaded another youngling he barely felt the guilty twitch in his chest he was trying so very hard to stomp out.

His master would be so pleased with him. He let out a mad cackle and lashed out at a Twi'lek girl who crumpled soundlessly to the floor as the lightsaber slid out of the cauterized hole in her chest, the realization of betrayal shining too late in her eyes as all light drained out of them.

"Go search the library and the training rooms. We may have missed some," he ordered and the Knights dispersed, leaving him to contemplate the recently deceased girl and the look in his eyes. That was what he loved the most, that moment of realization. When they saw that he was not Ben Solo, no matter how much they wanted him to be, he was Kylo Ren. They were so naïve, so stupid.

He was jerked out of his trance by the sound of a lightsaber coming to life, and through the dark lenses of his mask he saw the girl at the end of the hall. She held her blue lightsaber in a ready stance, glaring into his soul, and he was sure that despite the mask she knew who he was. In her eyes was not grief, nor fear, but anger. Hatred.

It almost broke him.

"Rey," he said softly, trying to keep the tears out of his voice.

"Why?" she sobbed, angry tears running down her cheeks, hands trembling around the hilt of the lightsaber. "We were your friends, Ben, why?"

Ben. Something inside him softened.

"Come with me, Rey. I can teach you," he begged. Please, Rey. Don't make me do this.

"After you killed them? You killed them, Ben, how could you?" she cried, and the accusation in her voice hurt more than a thousand knives.

He pulled his mask off and knelt down to her level. "I had to, Rey. I had to. But I can save you. Please, come with me."

Please don't hate me.

"How could you?" she repeated, voice cracking. "Your friends, Ben."

"I have new friends," he insisted. "They made me strong. They can help you, too."

"Strength?" she asked, gesturing with her free hand at the piles of dead children lining the hallways. "You-you call this strength?"

Children.

He'd killed children.

"Rey," he said, and his voice sounded strange in his ears, and he wondered when he'd started crying. "Rey, please don't make me do this."

"Do what? Are you going to kill me, Ben? Like you killed them?" she asked, almost calmly, and he wondered how she could possibly be more in control of her emotions than he was.

"I have to."

She shook her head. "No. You don't."

"I HAVE NO CHOICE!" he shouted, unsheathing his lightsaber again, the three points flaring to bloody life and burning the air around them, suddenly so angry at her serenity and he wanted to scare her because this would be so much easier if she was scared and not so maddeningly calm.

She didn't even flinch. "Yes, you do, Ben."

"My name," he said with a threatening stillness and just a small tremble in his voice betraying his inner turmoil, "is Kylo Ren."

Her fingers tightened around the hilt of her lightsaber. His was arcing downward before he could even think about it and before he could do anything to stop it but stare helplessly at what his hands were doing without his permission.

The blue and red sparks peppered holes in his gloves and stung his hands, and he stared in disbelief. She'd parried. Despite his great height and experience advantages, she'd held him off. He swung again, she stopped the blade midair. And again. And again.

He glared at her because this was so hard already and she was only making it harder and couldn't she just die already! and she only stared back with stony determination as she parried, blocked, cut back at him.

And then he had an opening, and he brought his lightsaber down on her exposed head, but just a moment before the deadly beam of light could burn through her skull he turned it off and knocked her unconscious with the hilt.

He could kill her. He should kill her. She was defenseless, and it was what his master had ordered. She wouldn't feel a thing. He held his lightsaber poised to strike over her prone body.

The strike never came.

He couldn't do it.

He sheathed the lightsaber again and scooped the girl up, gently, almost lovingly, carrying her through the carnage and into his personal ship, before calling the Knights back to inform them that all the Padawans were dead. He would make his dishonest report to Supreme Leader Snoke later. First he had a stop to make.

It was only a few moments before he found a suitable planet, fitting in a way. Jakku, neighbor planet to Tatooine, where his uncle and his grandfather had both spent their boyhoods. In mere minutes he had plotted a course and made the jump to hyperspace.

Just a few minutes after dropping back into ordinary space, the blurred streaks of stars returning to stationary dots, he was landing on the surface of Jakku. A barren desert world, close to nothing, overrun by crime. She'd be safe.

"I'll come back for you," he promised as he set the unconscious girl in a rare patch of shade. "Someday, I will, and you'll see."

He almost ran back to the ship, guilt knawing at a heart he wasn't supposed to have, and took off, disappearing into the atmosphere, running away from the girl, from his past, from the the accusatory glare still burning into his memory.

Back on Jakku, the young girl's eyes fluttered open and she scrambled to her feet, but by then all she could see was the blood-red engine disappearing into the vast emptiness of space.

Well, I made myself sob writing this, hope you like it. This is basically my headcanon on Rey and Kylo Ren's history until definitive information comes out in the next two movies.