Samm rode in silence for a moment, then shook his head—a surprisingly human gesture he must have picked up from her or Heron. “I don’t know how to describe it because I can’t imagine not having it,” he said. “It’s like not having eyes. You use your eyes for everything—vision is so important to human and Partial function that it colors every other aspect of our lives. Even that—the word ‘colors’ as a synonym for ‘affects.’ It’s a visual metaphor being used to describe something nonvisual. When you imagine someone trying to function without sight, that’s how I imagine someone trying to function without the link.”

“But vision fails all the time,” said Kira. “Blind people can still function in society, and I bet all of them understand metaphors like ‘colors.’”

“But blindness is still considered a handicap,” said Samm, “at least among Partials.”

“Humans, too.”

“Okay then,” said Samm. “And no one would argue that blindness is a stylistic difference, it’s literally a lessening of ability.”

“Take a look at this,” said Kira. She widened her eyes, making an exaggerated “surprised” face, and Samm didn’t respond. “Did you see it?”

“See what?”

“I just opened my eyes really wide.”

“You do that all the time,” said Samm. “Different parts of your face and body move constantly while you talk; Heron does it, too. I used to think she had a facial tremor.”

Kira laughed. “It’s called body language. Most of the social cues that you communicate with pheromones, we communicate with little facial movements and hand gestures. This means I’m surprised.” She widened her eyes again. “This means I’m skeptical.” She raised her eyebrow. “This means I don’t know something.” She shrugged, holding her hands to the sides, palms up.

“How do you . . .” Samm paused, in the space where a human would furrow his brow or wrinkle his lips—something to signify confusion—and Kira assumed that he was sending out “I’m confused” data through the pheromone link. “How do you teach that to each other? A new member of your culture, or a new child—how long does it take them to learn all these weird little hand signals?” He tried to emulate the shrug, looking stiff and mechanical.

“That’s like asking a Spanish speaker why they bother with all those weird words when it would be so much easier to just speak English,” said Kira. “Do you have to teach the link data to new Partials?”

“We haven’t had new Partials in years,” said Samm, “but no, of course not, and I think I see where you’re going with this. Do you really mean to say that this ‘body language’ is as inherent to human beings as the link is to Partials?”

“That’s exactly it.”