Merlin paled a little. "I don't know. I mean, I remember trying to do this with one of my friends in my home town. It didn't end up very pretty and his leg was worse off than if I hadn't done anything." He remembered how his friend, William, hadn't wanted to get into trouble. He said, you fix broken things, why not my leg? He had studied some anatomy since then, hoping if it came up again he might be able to do something, but he'd never tried it. He repeated the incantation without any power behind it, just to make sure he could pronounce it right.
"Are you sure you want me to try?" Part of him did think he could do it, but the bigger part was too scared to mess up. Shouldn't he try this first on an animal or something?