Now, these keys were too cumbersome to carry, but what point was there in leaving the key hanging from a nearby hook? Or even leaving it in the lock? One might as well not even bother with the lock at all in that case. And so, the key was entrusted to one of the household slaves, who wore it about their neck on a chain. The professor draws a circle on the chalkboard.

"What about the slaves?" I whisper to Nora. "They have the key. Master's not home. Won't they try it in the lock?"

We are sitting in the back row of the lecture hall. I am wearing flannel pajamas and stuffed lobster slippers; she is wearing a lemon-coated summer frock, and her legs and arms are covered with henna script. A band of green pearls circles her left wrist. Her bare feet are resting on the chair in front of us, and her toenails are rainbow chips of abalone shell.

"This is before curiosity was discovered," she whispers back.

"Was it now? I didn't realize there was such a time. Whatever did we do with ourselves before we stumbled upon that need to be nosy?"

"Lived without locks, I suppose."

"That's a circular argument, I think. Which came first then? The first lock or the first busybody neighbor?"

"Paranoia came first." The script on her left arm moves. Come on, Harry, play along with me.

"Of course it did. So what happened to the Wearers of the Key? Did their masters tire of feeding them, or did someone realize a scrawny ill-fed whelp wasn't the most secure of a security system?"

"Locks got smaller and more complex. The way everything did when the industrial revolution came along."

"Everything?"

"Yes. The world, most of all. It became harder to hide things."

"What about Pandora? Wasn't she the first to exhibit curiosity?"

"That was different," she says. "That was duty."

"Whose?" I counter.

However, during the late period of the Roman Empire, the ability to work metal became more widespread. Locks became more prevalent, and keys became smaller. The professor holds up his hand, showing the students the heavy band on his left hand (white stone set in silver and platinum). Keys were made to fit on rings.

Nora pretends to have not heard my question.

"Did she use a key?" I put my lips close to her ear. "Which key?"

"She found it," she replies, turning her face so that her lips are close to mine. Her eyes dance with the delight of confounding me.

"Where?"

"Who's curious now?"

"I could say the same thing about you," I reply. Remember when I first visited you in the hospital room? When you first asked all those questions.

Of course, Harry. I remember it because you do.

During the Middle Ages, that dark period following the fall of Rome, knowledge was power. The secrets weren't forgotten. They were hidden. In the monasteries and rectories, priests and monks bound their books with miniature locks. The only professions that thrived during the Dark Ages were the paper makers and the locksmiths. He clears his throat, tugging at his collar. His tie flutters against his narrow chest, a colorful ribbon descending from his neck. Both were keymakers, metaphorically speaking.

"She knew what was in the box." My lips brush against her cheek now. Her scent makes my throat constrict. "But she opened it anyway."

She raises her face, eyes looking up at the rounded dome of the lecture hall ceiling. "Why you suppose she did that?"

"Why did she?"

She laughs, and pushes me away gently.

The professor pauses in his lecture, and looks up at the two of us in the back. A number of other students turn in their seats. I am the only one who sees him pull the string of colored handkerchiefs out of sleeve, and transfer them to his coat pocket.

Thieves, he began again, pulling their attention away from Nora and me. Thieves became quite proficient at picking the simple locks—most of which were reliant upon gravity and a basic bolt system to be secure. During the Renaissance, the combination lock came into vogue, partially as a response to the ready ability of the nimble-fingered.

"Am I supposed to steal something?"

"Other than my heart?" She snorts into her hands, and words slip off her fingers. They fall too quickly, turning into pale birds that vanish like hummingbirds, and I cannot read them.

"Yes, other than your heart." I touch her hair. "What would I do with it anyway?"

She puts one of her inscribed hands on my chest. Put it here, Harry. You could put it here.

The early combination locks weren't random. They were primarily used in party games. Who can guess the combination? Five letters. Who knows?

Her fingers tap against my chest. Five letters. I know this key.

And then came the era of the great lockmakers. Bramah. Chubb. Pettit. Yale. Sargent. Following them, came the greatest key who ever lived: Harry Houdidi.

"She told him."

"Told him what?"

"After she opened the box, she told him the secret word."

Houdini put in hundreds of hours of practice. On every sort of lock imaginable. He didn't need a key. He didn't want a key. He just needed a thin strip of wire, and the self-confidence that he could undo what had been closed. Houdini was an Opener of Ways.

"'Believe.' Isn't that what he said he would tell her from the other side?"

Nora puts her hands over her eyes. As she smiles, the three words crawl across the back of her hands. Answer say answer. "Not Bess," she says. "Pandora."

"Who'd she tell?"

"The one who looks backward. The one who wasn't chained."

Who was the other Opener of Ways? The professor strides back to the board. With a few strokes, he draws the net of a hypercube. Christ. He hung on the beam, and the Spear was the Key that lifted his ribs, that opened his heart, and raised him up. The Spear was the Key.

"What am I supposed to do with the key, Nora. I thought it wasn't important. I thought it was a distraction."

"It is, because you won't be the one who uses it."

"Who will?"

She shakes her head. "No, Harry. Which door? That is the question you should be asking." Which door?

At the board, the professor is sketching absentmindedly as he drones on. The bottom hem of his tweed coat is frayed into ribbons. On the board, a picture of a scarecrow appears. It wears a crooked smile as it hangs on the cross of the hypercube.