Assassins Forest

Prologue

A boy sat alone on his bed. The door slammed behind him, putting a hold on the light that had fought away the darkness. A wave of cold air washed over him, the small window behind letting in a minuscule amount of moonlight. It was enough for him. The already confined room had never felt small like this. His knees merely 2 feet from the wall, and his back 3 feet from the other, he felt massive. His hair was a mess from his grandmother's constant "caring". Caring? His grandmother called her smacking, yelling, and pushing— caring, so often he didn't know what it meant anymore.  After all, she never 'cared' for his sister. His fists clenched and he closed his eyes. It had been so long since he had let himself feel mad. It almost refreshed him to let his anger take over. Grandmother had always let him wash her clothes and scrub her floors, promising him it was for his own good. His fists hardened while he tucked his sullen feelings away.
I can't, he thought, Anger is what got me here in the first place.
He let his mind wander away from the dreaded room, through the walls of the house, through the tightly wound fence and into the enclosed forest. This was a place where everything seemed to have a purpose, it was so organized. Here, he listened to the forest's chatter. He heard animals rustling in the bracken and trees talking to one another in their usual, hushed tone. A smile dared to show on his lips.
A small wail caught his attention. He relaxed his grip and focused on it. The room melted around him. The constant whirr of the fan above him became smaller and quieter, as though it had run out of power. The wail came from a young sapling, it's branches drooped low nearly digging into the soil. Sunlight had not been plentiful for this one. As he came closer, it seemed upset. Slowly, it's distant echoes filled his ears until it was all he could hear.
He sat, frozen. He felt his hands burn with millions of small needles and felt energy radiate from himself. He gasped and felt an ache in his side. Struggling to keep his composure, he turned around and felt for his window, hands still tingling fiercely. The tree shrieked as he felt his hands fly open and power flood through him.
The tree lessened its shouts. In fact, it seemed almost pleasant. The boy opened his eyes and to his surprise, he saw a massive tree shooting up out of the forest grounds. Another tree shot up out of the ground near it, branches climbing towards the sky. The boy felt himself being drained from helping the tiny plant grow. He couldn't stop it, the forest kept screaming at him to continue. Tree after tree started to wail at him, telling him to help them grow. The floor seemed to disappear from under him and he felt himself fall into the trees, unable to pull his mind away, he let himself go.
A hand suddenly gripped his shoulder, it tightened and then relaxed. Everything stopped at once. The screams silenced and his mind stopped reeling. He felt someone whisper gravely in his ear, "I can help you figure this out, as long as you help me in return-"...