It seems Ellis is content to watch, for a time. (A year ago, he'd stretched out on the ground while Mhavos had written reports too, fallen asleep to the methodic scratching of Mhavos' pen.) But the smearing of charcoal prompts some soft clearing of the throat, Ellis shifting as his attention sharpens.
phew
"Mhavos," he says. "Hold, a minute."