Gale struggled to find the right words. Why indeed? "because everyone deserves a second chance." He finally said, not entirely sure if he believed it himself. Mercy seemed to sense that, and she looked away from him when she spoke again.

"I have had enough of second chances. I have been given so many of them already, and I have thrown every one of them away, all in the hopes that papa would listen to me, just once, and stop with the insanity and the cruelty." She spat the last word as though it tasted foul on her tongue, and Gale saw her hands curl up, balled into tiny fists.
"You have no idea what I have seen, what I have done. My life, everyday, was like a never-ending Hunger Game, and I hated it. But you know what the worst thing is, Gale Hawthorn? You know what makes me shiver with horror everytime I think about it?" She paused for a second, looking at Gale as though he knew the answer to her question. When she recieved nothing, she continued, a savage grin breaking across her face, making her delicate features broken and distorted. Her voice was full to the brim of self-loathing, and she spat every word through her teeth.
"The worst thing, is not what I saw, not what I did, but the feeling that I got every time I hurt someone. I would get excited, Gale Hawthorn, do you understand? I used to love hearing those strangled screeches. I always made sure that I was the perfect little girl, just so that I could take my papa's hand in one of mine, my favourite voodoo doll in the other, and desend those stairs into the depths of Hell. Not because I was forced to, but because I wanted to. Because I was as corrupted and sick as the rest of them." Refusing to meet his horrified gaze, Mercy walked away from Gale to the rock on which a small white doll lay. She picked it up and carressed its long black hair lovingly, gazing at it with such intense love that for a fleeting moment, Gale was jealous of it. He mentally shook himself, remembering that she was a daughter of the Capitol. In the few seconds it had taken Gale to recover, Mercy had crossed the clearing again and was once again standing in front of him, the doll clutched tightly to her chest; she reminded Gale of a scared, lost little child. A sharp gasp wrenched through his lips when a small icy hand grasped his own, and when he looked at Mercy he saw that she was staring intently at him, an unreadable expression in her eyes. "What, what are you doing?" He stuttered. He recieved no reply, instead Mercy looked down at their entwinded hands, flipping Gale's so that his palm was facing upwards. Before he could protest, she pressed her doll into his hand, curling his fingers around its soft, worn material.
"Look, " she whispered, a smile creeping onto her face. Unable to help himself, Gale looked down at his hand, not entirely sure what he was expecting to see. Staring back at him were two big grey button eyes framed by short black hair. In its hand it held a bow, a quiver of arrows on its back.
"Ah!" Suddenly dropping the doll as though it had burnt him, Gale stepped backwards hastily, falling over a tree root and landing hard on his backside. He continued scrambling away as Mercy calmly picked up the doll, brushing dirt from its clothes; clothes that resembled exactly what Gale was wearing at that moment.
"Don't you like Waneta? She looks so much like you, don't you think?"

"What happened to that doll?" Gale gasped. Mercy only giggled. Almost casually, she pulled the doll, Watena, towards her, and Gale found himself being thrust off the ground by an unseen force, proppeled towards the girl who stood so calm, midnight blue orbs far-away as they watched his clumsy process.
"Stop it! Whatever you're doing to me, stop it now!" A look of hurt flashed across Mercy's face before being instantly replaced by a blank expression. Almost immediately Gale felt himself released from the invisible bonds.

Yes, she can do voodoo. =D Not sure where that came from, but it just popped into my head so I thought I'd go with it and see where it takes me.