Page 83 of Under Story

“Slowly, the plant becomes younger,” she continues. “A tree turns into a sapling, then a sprout. Eventually its genetic information is absorbed by other plants of the same species. Those young cells help the others to stay healthy.”

“I’m with you,” Eli says.

“Good,” she says, “because here’s where things get weird. Usually, in our world, matter that was living decomposes—but not always. If decomposition is interrupted, a fossil forms instead.”

“Right.”

“Here, a fossil is like a seed.”

“Now you’ve lost me.”

“Think of it this way. Fossils are out of step with time. Like any seed, they only grow under certain conditions. Scientists know that fossils will compose at some point in the future, but to find out when, they have to date them.”

“Which is what Laurel and Kwame Two were doing?”

“That’s my guess. They knew that Antarctica would be forested one day; they’d found the fossils to prove it. Laurel Two was trying to identify the conditions that enable the fossils to grow. I think that Kwame’s job is to estimate when that climate will come to be.”

Eli’s mouth opens slowly. “If plants compose, does that mean that animals do, too?”

Laurel nods. “A skeleton is a fossil that hasn’t yet been born.”

“Keep going,” says Eli.

Laurel does her best thinking in motion: when Silas was a baby, she walked with him strapped to her chest, dictating notes into an app on her iPhone. Now she paces in front of the fireplace.

“In our universe, decomposition begins when life ends. Blood becomes acidic; cell walls break down; fungi and bacteria chop proteins into pieces. Only bones are left, at least for a century or so; after that, they turn into dust. In this universe, though, bacteria and fungi glue molecules together. Cells form, then tissues, then organs.”

Eager, Eli cuts in. “Because of the laws of entropy.”

“What do you mean?”

“The arrow of our universe points toward increasing disorder,” he says. “Ice melts. Bodies age. Things fall apart. But this universe moves toward the Big Bang, and entropy is reversed.”

“Things build up,” says Laurel, catching on. “Molecules join other molecules. Complexity increases. But the process is noisy and prone to error, so most newborn adults have some kind of disease.”

“The same thing they died of in our world?”

“If Helen is any indication. Beth said she’s still being treated, so maybe that’s what happens in the white building. It could be a kind of reverse hospice—a nursery. And since the overtaker knew to bring Helen to Beth’s house, they must do genetic testing, matching newborns to their closest living relatives.”

“But what about new life?” asks Eli. “Babies…”

“Maybe the definition is different. Newborns are people like Helen, and the elderly are kids.”

“So people live for decades before they meet their parents?”

Laurel thinks about the mirror. “Well, it’s the opposite for us. You don’t know who your children will be until you have them. In this universe, the order is reversed. You take care of your parents, and then your parents take care of you.”

Eli presses his palms to the sides of his head. “Do you realize what that means? Everyone outlives their children.”

The chill she feels then goes down to the bone. “Eli, if I were alone here, I think I’d lose my mind.”

“Me, too,” he says. “You’re the only reason I’m fairly sure I haven’t already.”

Laurel drops onto the sofa. The cushion presses back against her thighs. In moments of overwhelm, she squeezes her own hand, reassured by its solidity. This time, she almost leans against Eli. The impulse spooks her. Their relationship is stable because they’ve sanitized it—and surely what she wants is just the comfort of another body. The next time Laurel sees Clare, she’ll give her a longer hug than usual.

—

An email confirms her spring course assignment: the Principles of Composition. Before she can design it, Laurel has to teach herself.