Check email at library.

Like a pet, the internet was something she would have liked to welcome into her home, but the wards scrambled most kinds of communicative technology—phones fritzed, wires crossed, and so on. The radio worked, and so did walkie-talkies, which was how the family hadcommunicated when the house had held them all, before Esther, and then Cecily, had left. The soundtrack of Joanna’s childhood was her sister’s enthusiastic voice in her ear, “Esther for Joanna! Do you copy! Roger that! Over and out!”

She looked again at the clock. It was time.

Back to the kitchen, where she took the little silver knife out of the drying rack. She didn’t look at the refrigerator as she passed it on her way to the basement, but she could see its colorful face from the corner of her eye, postcards magneted to every available surface. One for every month her sister had been gone. Ten years’ worth. Soon there’d be another. Each month Joanna collected Esther’s card from the post office and each month she told herself not to put it up, but she could not stop herself from adding to the collection on the fridge, even though she hadn’t talked to Esther since their father had died.

Esther had an email address, though she seemed to check it rarely, and after Abe’s death it had taken Joanna five separate variations ofEsther, we have to talk,before Esther had written back with a phone number. Joanna had gone to her mother’s house outside town and called from Cecily’s kitchen floor, one hand pressed to the cool tile and her mother’s cell phone pressed to her ear. When Joanna told her what had happened, Esther had sobbed instantly and noisily, her cries raggedly vocalized, her breath phlegmy in her throat; so exactly the way she’d cried as a little girl that briefly Joanna had felt close to her.

Then she’d asked Esther to come home.

Begged her, actually. Screamed at her, frenzied with grief, while Esther had wept, repeatingI can’t, I can’t, I can’t,until Cecily had prized the cell phone from Joanna’s hand and stepped away to speak to Esther herself, voice low and soothing.

Joanna had tried to forgive her sister for leaving in the first place, for vanishing with no explanation, but she could never forgive her for this: for refusing to come back when Joanna had needed her the most, whenshe was the only person alive who’d be able to read the book that had killed their father, the only one who could have offered Joanna answers. The only one who could have offered comfort.

Joanna had never reached out to her again.

Nevertheless, the postcards kept coming, one for Cecily and one for Joanna, faithful as the moon.

A skyline bright with an old neon sign for Gold Medal Flour: “Dear Jo, Here in Minnesota, everyone’s got a sauna in their backyard. I think Vermont should get on this train. Your Northern blood will thank you. Love, your sweating sister, Esther.”

A reproduction ofThe Two Fridas,the painter’s dual hearts connected by delicate, bloodied veins: “Querida Jo, si quieres entender este postal en total, tendrés que aprender español. I’m here in Mexico City, bungling verb conjugations and failing at finding any information on my mother’s family. Un beso muy fuerte de tu hermana errante, Esther.”

The last one had penguins. “Dear Jo, Did you know that the word ‘Arctic’ comes from the Greek word for bears?Antarctic meansnobears. So remember not to picture me among polar bears, if you ever picture me at all. Love, your freezing sister, Esther.”

How many nights had Joanna spent sleeplessly staring at these postcards, rereading words she already knew by heart? How many hours had she spent at the library or on her mother’s computer, looking up all these faraway sights she would never see? She was an expert in every place her sister had been. An expert in mountains she’d never climb, seas she’d never swim, cities whose streets she’d never walk.

She didn’t bother turning on the light when she tugged open the basement door. Even without years of sense-memory to guide her feet, the growing golden hum would lead her. In the black she made her way down the creaky wooden steps into the mold-fragrant dampness, moving past the pale shape of the washing machine to where the tarp was stretched across the floor, held down by cement blocks, the trapdoor waitingbeneath it. She pulled it open with a yawn of old wood and descended the second set of steps.

The hum filled her head.

At the bottom stair she paused to feel along the cement wall for the light switch, and an instant later the short hall was illuminated. The door to the collection was made of bare steel with vinyl weather-stripping at the bottom and a deadbolt above the handle. The key, strung with red ribbon, hung from a nail to Joanna’s left, and she turned it in the lock with a familiar clunk.

It took her a moment, as always, to acclimate to the roar that surged in her mind’s ears, a sound she had attempted to describe to her sister and mother more than once but never could. Like being filled with golden bees that were all actually one bee, which was actually a field of shining wheat rustling beneath a blazing sun. It was a sound but not a sound. It was in her ears but it was in her head. It was like tasting a feeling and the feeling was power.

“Seems uncomfortable,” Esther had said.

It was.

It was also magnificent.

The door closed behind Joanna and she leaned against it, eyes shut, waiting until the sound was less physically overwhelming. Then she turned on the overhead light. It was warm down here, always 66degrees Fahrenheit with 45 percent humidity—this was where all her electricity and gas went. At the front of the square room—what Abe had called “the business end,” although no actual business had ever been conducted—sat a small stainless-steel sink, several behemoth filing cabinets, a towering set of oak shelves that held jars and jars of herbs, and a vast walnut desk they’d found at an estate sale in Burlington many years ago.

The rest of the room was filled with the books themselves.

There were five wooden bookshelves, each over six feet wide and taller than Joanna, each fitted with airtight glass doors. They sat in rowson an old red wool carpet, a replacement for another red carpet that Joanna’s mother had burned a decade earlier, though Joanna didn’t like to think about that day. Taped at the end of each shelf, like a Dewey Decimal plaque, was a list of which books could be found on which shelf and in what order.

Some of the larger folios lay flat but most books were held in bookstands, and Joanna dusted them every morning with a paintbrush and examined them for signs of damage, for silverfish, bookworms, and mice, though the basement was airtight and pests hadn’t been a problem for years. She had been doing this since her father had first tested her talents at five years old.

The books were roughly organized by approximate date, though they were all old. The oldest in Joanna’s collection was circa 1100 and the newest from 1730. She didn’t know what had been lost in the past few centuries: Was it the knowledge of how to write the books, or the magic that had once filled them? This was a question that had plagued her since she was a child, a question to which Abe had always claimed not only ignorance, but incuriosity.

It’s not for us to ask how.

Abe seemed to think protection was at odds with knowledge, as if they could not properly protect the books if they knew too much about them. This belief—in silence, in ignorance—extended through the books and into other aspects of his life, particularly where his daughters were concerned. Keeping them in the dark, he seemed to believe, was tantamount to keeping them safe.

“It’s a trauma response,” Esther had said once to Joanna, with that annoying air of superior wisdom she’d adopted in adolescence. “He thinks if he talks about bad things that have happened, more bad things will happen.”

This sanguine analysis came after the many less-than-sanguine years Esther had spent begging to know more about her mother, Isabel, about whose death Abe would only ever share the same scant details: how hehad come home one day to their apartment in Mexico City to find Esther screaming in her crib, all their books gone, and Isabel shot dead on the floor.