He drives them to a copse of spared hardwoods in the bottoms of a slow stream.

But by her second year, the catch becomes clear. In a seminar on forest management, the professor declares that snags and windthrow should be cleaned up from the forest floor and pulped, to improve forest health. That doesn’t seem right. A healthy forest must need dead trees. They’ve been around since the beginning. Birds turn them to use, and small mammals, and more forms of insects lodge and dine on them than science has ever counted. She wants to raise her hand and say, like Ovid, how all life is turning into other things. But she doesn’t have the data. All she has is the intuition of a girl who grew up playing in the forest litter.

Soon, she sees. Something is wrong with the entire field, not just at Purdue, but nationwide. The men in charge of American forestry dream of turning out straight clean uniform grains at maximum speed. They speak of thrifty young forests and decadent old ones, of mean annual increment and economic maturity. She’s sure these men who run the field will have to fall, next year or the year after. And up from the downed trunks of their beliefs will spring rich new undergrowth. That’s where she’ll thrive.

She preaches this covert revolution to her undergrads. “You’ll look back in twenty years, amazed at what every smart person in forestry took to be self-evident truth. It’s the refrain of all good science: ‘How could we not have seen?’”

She sets the table and sits down to a meal that smells like health itself. The beauty of the plan is that no one will know. Every year, amateur mycologists mistake young A. bisporigera for Agaricus silvicola or even Volvariella volvacea. Neither her friends nor family nor former colleagues will think anything but this: she was wrong in her controversial research, and wrong in her choice of fungal fruiting bodies for her dinner. She brings the steaming forkful to her lips.

Something stops her. Signals flood her muscles, finer than any words. Not this. Come with. Fear nothing.

The fork drops back to the plate. She rouses as from sleepwalking. Fork, plate, mushroom feast: everything turns, as she watches, into a fit of madness, lifted. In another heartbeat, she can’t believe what her animal fear was willing to make her do. The opinion of others left her ready to suffer the most agonizing of deaths. She runs the entire meal down the garbage disposal and goes hungry, a hunger more wonderful than any meal.

Her real life starts this night—a long, postmortem bonus round. Nothing in the years to come can do worse than she was ready to do to herself. Human estimation can no longer touch her. She’s free now to experiment. To discover anything.

She stands in the clearing at the top of the rise, looking out over a shallow gully. Aspens everywhere, and it boggles her mind that not one of them has grown from seed. All through this part of the West, few aspens have done so in ten thousand years. Long ago, the climate changed, and an aspen’s seeds can no longer thrive here. But they propagate by root; they spread. There are aspen colonies up north where the ice sheets were, older than the sheets themselves. The motionless trees are migrating—immortal stands of aspen retreating before the latest two-mile-thick glaciers, then following them back north again. Life will not answer to reason. And meaning is too young a thing to have much power over it. All the drama of the world is gathering underground—massed symphonic choruses that Patricia means to hear before she dies.

She looks out over the draw to guess which way her male, this giant aspen clone, might be headed. He has been roving around the hills and gullies in a ten-millennium search for a female quaking giant to fertilize. Something on the next rise punches her in the chest. Carved out from the heart of the spreading clone, a housing development sits among a ribbon of new roads. Condos, a few days old, cut through several acres of the root system of one of the earth’s most lavish things. Dr. Westerford closes her eyes. She has seen dieback across the West. Aspens are withering. Grazed on by everything with hooves, cut off from rejuvenating fire, whole groves are vanishing. Now she sees a forest, spreading across these mountains since before humans left Africa, giving way to second homes. She sees it in one great glimpse of flashing gold: trees and humans, at war over the land and water and atmosphere. And she can hear, louder than the quaking leaves, which side will lose by winning.

Three weeks later, she’s near the same spot, pulling invasive plants. The thick, furry twigs of ailanthus suckers leave her fingers stinking of coffee and peanut butter. She climbs a switchback at a good clip and runs into the two researchers again. They’re several yards up the slope, kneeling by a downed log. Before she can flee, they see her and wave. Caught, she waves back and hikes up to them. The older man is on the ground, on his side, popping tiny creatures into specimen bottles.

“Ambrosia beetles?” The two heads turn toward her, startled. Dead logs: the topic was her passion once, and she forgets herself. “When I was a student, my teacher told us that fallen trunks were nothing but obstacles and fire hazards.”

The man on the ground looks up at her. “Mine said the same thing.”

“ ‘Clear them off to improve forest health.’ ”

“ ‘Burn them out for safety and cleanliness. Above all, keep them out of streams.’ ”

“ ‘Lay down the law and get the stagnant place producing again!’ ”

All three of them chuckle. But the chuckle is like pressing on a wound. Improve forest health. As if forests were waiting all these four hundred million years for us newcomers to come cure them. Science in the service of willful blindness: How could so many smart people have missed the obvious? A person has only to look, to see that dead logs are far more alive than living ones. But the senses never have much chance, against the power of doctrine.

“Well,” the man on the ground says, “I’m sticking it to the old bastard now!”

Patricia smiles, hope pushing through the ache like a breeze through rain. “What are you studying?”

“Fungi, arthropods, reptiles, amphibians, small mammals, frass, webs, denning, soil. . . . Everything we can catch a dead log doing.”

“How long have you been at it?”

The two men trade looks. The younger man hands down another sample bottle. “We’re six years in.”

Six years, in a field where most studies last a few months. “Where on earth did you find funding for that long?”

“We’re planning to study this particular log until it’s gone.”

She laughs again, a little wilder. A cedar trunk on the wet forest floor: their grad students’ great-great-great-grandchildren will have to finish the project. Science, in her absence, has gone as crazy as she always thought it should be. “You’ll disappear long before it does.”

The man on the ground sits up. “Best thing about studying the forest. You’re dead by the time the future can blame you for missing the obvious!” He looks at her as if she, too, is worth researching. “Dr. Westerford?”

She blinks, as baffled as any owl. Then she remembers her uniform badge, on her chest for anybody to read. But that Doctor. He could only have gotten that from her buried past. “I’m sorry,” she says. “I don’t remember ever meeting you.”

“You haven’t! I heard you talk, years ago. Forest studies conference, in Columbus. Airborne signaling. I was so impressed, I ordered offprints of your article.”

That wasn’t me, she wants to say. That was somebody else. Someone lying dead and rotting somewhere.

“They hit you pretty hard.”

She shrugs. The younger scientist looks on like a kid on a visit to the Smithsonian.

“I knew you’d be vindicated.” Her bafflement is enough to tell him everything. Why she’s in the uniform of a wilderness ranger. “Patricia. I’m Henry. This is Jason. Come visit the station.” His voice is soft but urgent, like there’s something at stake. “You’ll want to see what our group is doing. You’ll want to learn what your work’s been up to, while you were gone.”

A duet ensues: the bright, pert, human come-on, followed by the logy but obliging bird, hidden in the trees.

Hulking conifers that sprout adventitious roots high in the canopy that dip back down to feed on the mats of soil accumulating in the vees of their own branches.