The Wall soars over my head. All sixty feet of it are pock-marked with moss tunneling along the mortar and I have to lean back to see the iron spikes that crown the thick gray stones. Glossy, broad-leafed ivy has a toehold in the fissures of the rocks, but it only solidifies the permanence of the Wall. It is simultaneously impressive and terrifying. Immemorial. A frisson of apprehension raises the hair at my nape.

My grandmother used to lull me to sleep with stories about how the world was before the Wall was erected. Tucking my eight-year-old self into bed, she would recall her own grandfather's stories of the war on technology, and how they adapted in the aftermath. Her blue-violet eyes, so much like mine, shone in the late lamplight, lost in the past as she smoothed wisps of hair from my forehead, whispering in the dim lamplight.

"Remember this, Sophie. The Wall is a necessary evil, cutting us off from the rest of this savage world. It allowed our ancestors to rebuild a civilized community, rich in newfound industrial science." I feel her lips on my temple as I recall her words. We have survived when the rest of the world fell apart, only because our authorities have punished those who have Breached the Wall.

I shudder at the thought of the wild, untamed Outlanders circulating the Wall, striving for a Breach to destroy us. Once in a blue moon, one of the rugged barbarians will make its way past the Wall, through the woods, and over the levee into Herald. The most recent invader made it all the way to Market Circle before the military caught him, skinny and snarling and half-starved. The Council preaches that they are barely human, and from my experience with them, I couldn't agree more.

"It's so old," Markee exclaims. My best friend all but skips to the base of the Wall, her red waves bouncing behind her. She moves her hands over the rough stones, admiring the ancient strongholds. "Imagine how long it took to build this thing!"

It's the first words she's spoken in half an hour, and her silence was beginning to worry me. Markee is the talker and I am the listener—that's just the dynamic we've always had. She has been my best friend since we started at the same school, grew up in the same neighborhood, and now we are two teenagers spending the last summer before Job Placement sneaking around unpopulated, historic no-man's land that has every cell in my body on edge.

"We shouldn't even be here," I mumble, shaking my head in acceptance. Venturing past the levee isn't a crime, but it is highly dangerous. The soldiers don't patrol this far into the woods. There is only one reason I agreed to step foot past the levee: there is no stopping Markee from going, and heaven knows what trouble she would get in if she went alone. Shaking off my unease, I warily approach where Markee is motioning me over.

"Sophie, come look at this," Markee says. She's crouched low to the ground inspecting the base of the Wall. My feet drag as I draw near. To think that only a few feet of stone separates Herald from the vicious Outlands ties my stomach in knots.

My blood freezes in my veins when I realize what Markee is inspecting. A few feet below the base of the Wall, there is a hole big enough for a human to squeeze through. I'm not sure if it's the fact that we just stumbled upon an Outlander crossing or the excitement in Markee's eyes that makes me more nauseous. It is uncanny to me how she could possibly find joy in this.

Markee lies flat on her stomach and peers through the hole in the Wall, trying to glimpse the Outlands. "I don't believe it."

"What do you see?" A drop of curiosity seeps through my fear. Scrambling to join Markee, I lie on the ground next to her and peer in the shoulder-wide space. All I see is blackness, for the hole is sealed shut with concrete. The knot in my belly unfurls as Markee hops up from the ground and exhales sharply, kicking up a layer of fallen leaves in her typical over-dramatic way, but I grimace. The Outlanders are like dogs tunneling under a fence.

It's not until I'm up and dusting myself off that I realize the extent of Markee's displeasure and peculiar reaction. Her face is red and pinched into an expression balanced on the edge of anger and the verge of tears. Her arms are folded across her chest, not even bothering to wipe the dirt from her clothes. Her disappointment is a chasm between us.

"What's wrong?" I ask, confused by her behavior. "Why are you so upset?"

"I'm not." Markee schools her features into a mask of annoyance. "It's nothing."

Disappointment slam-dunks itself into my heart. My best friend has a secret. One that I'm not in on.

For as long as I can remember, Markee has wanted to be Placed as an emergency medical responder. While she slept through history classes, her attention never wavered during biology and chemistry lessons and she even volunteered at the hospital with her father.

That kind of experience translates to purpose in Herald. Never before has she been interested in any other future, but so far this summer, she hasn't taken a single shift at the hospital. For the past few weeks, she's begged me to accompany her to the library, the town's sole museum, and now to the Wall itself. I hadn't thought anything of it, until now.

There's a nagging itch at the back of my brain as my mind connects her sudden indifference toward our impending Job Placement to her newfound interest in history.

The silence between us is thicker than Grandma's bread pudding as we weave through the trees on our journey home. Normally Markee's grit makes up for my taciturn nature, but for the first time in a long time, awkwardness wedges between us. I chew the inside of my cheek, the stretching hush eating at me every second I am unable to fill the space with words. Silence does not fit her.

My feet slow to a stop. I have to say something.

"Why did you want to visit the Wall? You've always hated Herald History lessons."

At first, she gives no sign of having heard me. Then she halts, turning to show her face wiped clean of her earlier frustration. "I just wanted to see it in person. The pictures in the textbooks don't do it justice." She shrugs, but her eyes tell me a different story.

"Just drop it, okay?" Markee says, but then I nearly jump out of my skin at the sound of something crashing through the woods. Whipping around, I scan the woods for what it might be, but the underbrush is too thick to see more than a few feet in any direction. It makes too much noise to be a rabbit. Maybe it's one of the wild boars the Rangers have been tracking. A trickle of sweat drips down the back of my neck at the thought of their cloven hooves trampling toward us, tusks ripping through anything in their path, including us in it.

Markee and I exchange glances as the crunch of vegetation grows louder, nearing us at a terrifying speed. It motivates me to take a step back, muscles tense in preparation to bolt. As if we were repelling poles of a magnet, Markee steps forward and plants her feet.

"Ready yourself," she whispers, putting her fists up in a defensive stance. She looks every inch a pit fighter, down to her determined brow. Fear is absent from her face. I can't help but feel shadowed by her in this moment, her bravery overwhelming my cowardice. I am not strong. I have no raging fire. I am a single drop of blue water, easily overlooked and never able to quench one's thirst. I am hidden behind the great wall of fire called Markee.

For a moment, I remember Markee as an elementary school student, doodling on the school desk during class. She wore her hair in fiery twin braids when she sat next to me in the cafeteria, offering to trade her loaf of bread for my carton of milk. I hear her mouthing off to the teacher for giving me detention when the boy behind me was the one throwing paper balls. The young, naïve girl that used to be Markee stands before me now as a vibrant, headstrong pillar of flame, eager to be set loose.

A shiver of something dark and ugly winks to life in my gut, and I realize that I am vehemently envious. Shame slithers into my belly, coiling like a serpent looking to strike.

With thundering steps, the great noise is upon us. Through the foliage bursts a scraggly, mud-covered man. His eyes are round, with dirt-crusted eyebrows lifted in surprise. He halts, chest heaving and eyes darting for an escape route. I am close enough to see the sweat trailing dark brown lines through the dried mud on his forehead, and the bright red splash of blood on his ear.

"Are you okay?" I gasp at the stranger. "You're bleeding." I shuffle toward him and lift my hands before dropping them uselessly. I glance between him and Markee, who hasn't moved an inch. She's the one with medical experience, why does she have to freeze up now? I grimace at the blood coating the side of his head and seeping down his neck before soaking into his collar.

"Sophie, his clothes," Markee whispers. I have to squint to make out the state of them beneath the caked filth. His shirt is hand-sewn, the cloth simple with crude seams. His pants are the same, with a worn-out drawstring belt to hold them on his bone-thin hips. The garments were not made for style, but necessity—no one inside of Herald would wear such unrefined cloth. The tingling at the base of my neck signals that something is very, very wrong.

My eyes meet his in vivid clarity. His mouth opens to say something, the look on his face one of bewilderment before he takes a quick half-step toward me. I jump back, ice-cold fear gripping me as realization seeps into my brain like dark ink. Markee grabs my arm and tugs me to her side, gazing at the man before us with guarded eyes.

"You," Markee starts, her voice resonating in the suddenly all-too-quiet forest. "You're an Outlander."