“A question. We swim in a great arc southwest to midocean, then another arc northwest to our destination. Think how much faster it would be if we simply cut straight across the ocean like this.” She ran the edge of her thumb across the chart in a swift motion. Elem stepped back and gasped, her crest flaring red.

“Impossible!” Modifiers of despair and fear. “What you suggest is . . . unnatural. For short periods, yes, as we do now, or crossing from one island to another, then it is in order. But nothing moves in a straight line. The sea creatures follow the currents of the sea, the birds the invisible currents of the air. Such a course that you suggest, why—it goes against nature. The uruketo would have to be forced away from the currents, though at night it would drift with them, then in the morning recalculation . . . plainly impossible!”

“A simple query of scientific interest, Elem, compose yourself. Since you are a worker-with-knowledge, for the greater good of your labors, I will tell you of the two different states of matter. Or do you already know Atepenepsa’s law?”

“Humble-ignorance, desire-for-input.”

“Stated in its most basic form, invisible matter moves in straight lines, visible matter does not. Remove the glaze from your eyes and close your mouth—you are a picture of fargi stupidity! Do you know of invisible matter?”

“No . . .”

“Lump of ignorance! Gravity is invisible—if I drop this chartweight it goes straight down. That-which-carries light is itself invisible and it moves the light in a straight line from object to eye. Inertia is invisible, yet it keeps a moving object . . . enough. I see that this is all beyond you. Do not feel shame for your imbecility. There are very few Yilanè like myself who have no intellectual limitations. Now, to our course. What lies here?”

Ambalasi placed her splayed fingers and thumbs upon the empty area of the chart beyond Maninlè, south of Gendasi*. Elem gaped. “Nothing, nothing at all.”

“Empty-of-mind, unconscious-of-being-alive! Must I teach you your own speciality? What are these on the chart, here and here?”

“Currents, ocean currents of course.”

“Wonderful. Now, amplification-of-detail, what causes currents?”

“Temperature differentials of sea water, wind, planetary rotation, impact on coastlines, gradient of ocean floor . . .”

“Good. Now these currents, here and here, examine them closely. They do not appear out of outer darkness so suddenly. Trace them backward.”

“I see, I see! Great Ambalasi you have drawn me from ignorance as a fargi is drawn from the sea. There must be a large mass of land here, where you have indicated. Though no one has ever seen it or recorded it—you have deduced its existence from these charts . . .”

As the significance of this was driven home, Elem lowered her head and signed from lowest-of-low to highest-on-high, as she suddenly realized that Ambalasi knew as much as she did of navigation. Perhaps more. Ambalasi nodded, accepting the awareness.