[ give him a moment. he scratches at his jaw and cheek as he paces up and down the line of equations, careful not to step to close and mar them. he's got some stubble on his face now and it itches. his eyes light up when he does, indeed, see the problem, or at least he thinks he does. ]

Except there's no limbs missing, nothing to heal, nothing to grow so the energy usually spent on doing those things has no where to go, nothing to do. You've got to divert that somewhere else, somewhere that isn't harmful.