“Think about how versatile mushrooms are for a minute,” he says. “I just read this research study in the National Library of Medicine about fungal computers. Basidiomycetes. It’s fungi they think has the electrical and thermal and chemical capability of computing and networking data. That’s not science fiction. It’s science. And I recently did a consult with Boeing, another with an architectural firm—they’re thinking about trying to make things out of fungus. Everything from biomes on Mars to houses here in Seattle. Because some fungus is like wood. And some is foamy. And some is more pliant, like a polymer. It would be ecofriendly, obviously, but you could also repair elements of a structure by simply regrowing them. Is a fungus city any crazier than what we’re seeing right now?”

“But,” she says with a hard swallow, “are you saying this isn’t her? It’s just a Mia-shaped house? A piece of architecture?”

“No. I’m trying to say it’s her, but it’s not just her. It’s more than her.”

Nora returns to their daughter and Jack follows. Mia is staring at them. Maybe her mouth trembles slightly, the beginning of a smile. Whether she understands any of what they’re talking about, he doesn’t know. They touch her, squeezing her shoulder, rubbing her back, as if to remind themselves she’s real.

Nora says, “You said they each get something out of the relationship.”

“I did.”

“So what is Mia getting out of it?”

“What are we getting out of it, you mean. Because this isn’t just about her. It’s about humankind. She’s just one sample. One case study of what could be many.”

“Don’t call our daughter a case study. You sound like them,” she says, nodding toward the observation window.

“Sorry.”

“What is she—what are we—getting out of this relationship?”

His shoulders rise and fall in a shrug. “Maybe,” he says, “the chance to survive.”

“Survive what?”

“What’s happening in Seattle . . . I was thinking of it as a contagion before. But maybe there’s a better word.” Nora and Mia are both staring at him intently when he finally says the word: “Invasion.”

21

Annabelle had a brother. A twin. Named Adam. They looked so much alike—blond-haired, blue-eyed, always a pink flush high in their cheeks—that throughout their early childhood, people had trouble telling them apart. One of them might have a distinguishing freckle and one of them might have a scar on one elbow, but nobody could ever remember which feature equaled which kid. The twins enjoyed the confusion they caused so much that they styled their hair the same and wore each other’s clothes and sometimes swapped classrooms at their elementary school. This was in the Houston suburbs, where the roads ran straight, the lawns were an unspoiled green, and the houses all shared a similar design. People delighted in sameness.