She stops and takes a small vial out of her pocket. “If you ever get lost, remember: water flows downhill.” Opening the vial, she pours the liquid it contains onto the ground. It rolls in a small trickle to the right. “You can follow it to the Vault’s other entrance.”

“It’s all downhill from here,” I say. “Got it.”

“Exactly.” She winks. “This way.”

We make two more lefts, then a sharp right, and I’m already lost. The corridors are all practically identical.

“Here we are,” Allard finally says.

She stops abruptly, and I almost bump into her.

“Where is here?” I ask.

“This is the Crypt. Our library.” She pulls open a rusted metal door and ushers me inside. “It’s modeled after the International Spy Museum in Washington, D.C., and contains hundreds of code-breaking machines and all sorts of gadgets. Are you ready for your first lesson?”

Inside, the space is shockingly modern, with polished cement floors and lit-up display cases containing briefcases, old-fashioned cameras, and antique computer keyboards.

“I guess so…”

She closes the door and leads me past a fingerprinting display. “It’s imperative you learn to transmit messages that won’t be intercepted. You’ll need to learn to code and decode. This place is an amazing resource—you can check anything out. We have Enigma machines and ciphers dating back to medieval times. Those are located back here.” She pushes open another door, and the air sucks in around us, becomes colder. “These are the archives, modeled after Yale University’s Beinecke Rare Book and Manuscript Library.”

Dozens of individually lit bookshelves rise in front of us, forming a massive cube encased in glass. The surrounding walls are made of paneled marble, and brown leather couches are scattered at the base of the cube, arranged next to gold-framed rectangular tables.

As we enter, a boy about my age looks up from a massive book he’s studying on one of the tables.

Having expected to be alone, I almost jump out of my skin.

He slams the book shut and leaps to his feet.

“Garrett,” Allard exhales. “It’s good to see you.”

I’m instantly self-conscious. Terrified he’ll recognize me as Ella, I get busy studying my toes. Even though my hair now finishes in a jagged crop above my shoulders, and beneath my angled bangs, a row of white stars explodes over my black eye. I feel his stare and I imagine he sees right through me. He’s a thief, after all; they’re perceptive.

“You, too,” he says.

“Sorry to interrupt,” Allard says.

“It’s fine. I was on my way out.”

“You don’t have to leave.”

I venture a peek at him. Dark, messy hair falls across his forehead, and three smeared black bars are painted under one eye. He’s wearing a jumpsuit like mine, but his stretches across wide shoulders, his sleeves rolled up, revealing strong forearms. His smoldering green eyes pop, amplified by exhausted red rims, and his full lips purse in a frown. If I were remotely able to find anyone attractive at this moment, I would surrender at his feet. Something about him has me buzzing like there’s static electricity in the air, and I wouldn’t be surprised if my hair was standing on end.