Ah. That explains that. They straighten enough to look down the row of cells, wondering for a short instant if they want the other prisoners to hear all of this. It's not for San's sake, but their own.

Their foot scuffs the floor, and they start talking as though they'd never hesitated.

"He can make bones out of thin air. If you touch them, they'll hurt. If he hits you with them, or runs you through, they'll hurt a whole lot more."