Evolution. Mutation. Genetic drift. Natural selection. Dr. Tabb is speaking, explaining, but her words flow into one ear and out of the other.

They evolved into Skinwalkers, my mind echoes.

I study the open-faced book, examining the picture of the macaque. I imagine the Skinwalker in my mind so vividly, and I begin to see the similarities. They are both large-bodied with long, gangly limbs, elongated skulls, and huge, sharp teeth. But that is where the similarities end. As the macaque is cloaked in wiry fur, Skinwalkers exhibit pale, smooth skin from head to toe. Skinwalkers seem to walk a bit more upright than their ancestors, but still crouch in typical knuckle-dragging fashion. That is only a few obvious physical attributes; what psychological differences are there? And just how did they come to take over society?

The uneasy tingle in my stomach intensifies. "What happened?"

Dr. Tabb shifts in her seat. "As far as scientific experiments go, there is some amount of danger when working with live specimens. Remember the aggression observed in the experimental group?" I nod, fighting back a shudder.

"Anger can fuel aggression, and sometimes, it only takes a small mistake to change the course of history." She rests her chin on her age-spotted hand, observing me as she continues. "See, the day of the Breach, researchers were here at the former University Medical Laboratory attempting to obtain the vitals of their experiment when one of the macaques lashed out, injuring and infecting personnel. It and the twenty-three others succeeded in violently breaking out of the facility."

A chill rips through me at her words, and I nearly fall out of my chair. "They escaped?"

"Escaped and devastated and infected and reproduced," Dr. Tabb sniffs.

Dr. Tabb continues, but my mind is left behind, whirling with the thought of the havoc wreaked on the people of Natio. I can almost see the white lab coats flailing behind as people ran. I can almost hear the screams—of both human and beast. How many people were left in their wake?

My brain finally tunes in to Dr. Tabb's voice at the mention of the Neo-Plague.

"If they didn't succeed in finding a vaccine, what did the people do?" I ask, looking between Rhett and Dr. Tabb. "How did they survive?"

Rhett's eyes soften. "They didn't."

Dr. Tabb clears her throat. "Hundreds of thousands perished before the Neo-plague died off. After all, a virus cannot survive without a host." The smallest of smiles turns up her wrinkled face. "But over time, some adapted. Fought back. Survived. And here we are." She holds out her hands, beholding the three of us.

I am awed by the sheer tenacity of the human race. Though posed with an unexpected, volatile apex predator, the ancestors of the Outlanders somehow found a way to eek out a living. "Someone had to rebuild, right?" I grin.

Rhett shakes his head. "Yes, but not everyone did. There were people who evacuated the city, particularly the bourgeoisie who were wealthy enough to pack everything up and begin anew."

I look at him, forehead wrinkled in confusion. "But how would they escape the disease? Skinwalkers? Where could they go? It's not like there was a city free of the Neo-plague."

"Of course," Dr. Tabb remarks. "Unless you create your own exclusive civilization. Actually, you might have heard of it." Dr. Tabb's lips stretch wide. "They named it Herald."

A second passes, then another before the words register in me. Then, I briefly wonder if I heard her right. A glance to Rhett's face confirms it, and I feel myself slumping, drooping toward the ground like melted ice-cream.

"It's okay, Soph," Rhett soothes, letting me lean against him. Dr. Tabb's revelation knocked the zeal right out of me, but the more I think about it, the more it makes sense. It's like I've finally gotten enough puzzle pieces to make out an image.

But what I see is positively heinous.

"It's the truth, isn't it?" I ask, my voice a little bird.

Rhett nods against the top of my head. "Our ancestors created Herald. It was a sanctuary from the diseased. From the Skinwalkers." He squeezes my shoulder, but I see the wall as what it is: a haven only for the privileged.

His words paint a picture in my mind, a montage of stonework and burning forests. Classes and textbooks and paragraphs and lies. It all bleeds together, and I squeeze my eyes shut. Face it, I think. This is what humanity looks like.

I shake my head. "That's not survival," I mumble. "They ran away, abandoned half of their community, and kept the less fortunate from refuge. How is that acceptable?"

Dr. Tabb hums. "Yes, quite unfair if you ask me." She flips through the pages of the book lying in front of her nonchalantly. "To Herald a new beginning. But try not to look at it that way. It worked. Self-preservation wins again."

"But the—the Outlanders! They did nothing wrong!" Disgust curdles my breakfast when I realize I came from those bourgeoisie. My ancestors cowardly and selfishly ran away.

My brain is taking off and I can't sit still. Sliding off the bench, I begin to pace. For centuries, we have been keeping countless technologies and life-saving knowledge to ourselves under the guise of manifest destiny. We were the chosen ones, they told us. We survived. We were right. But Herald is wrong.

"Is that why you need me?" I throw the question at Dr. Tabb so suddenly, it takes her a moment to comprehend. "Did you bring me here to give you the knowledge from inside Herald? Technology?" My gaze whips to my brother. "Mom and Dad may know something that could help."

The cracks at the corners of Dr. Tabbs eyes deepen with her smile. "No, child. We need nothing more from Herald now that we have you."

"But what can I do? I don't have the knowledge or—or the expertise or any of that science-y stuff."

"Not to worry." She stands, holding out her hand for mine. "All we need is a little bit of blood."

My feet move back a few steps before I realize it. "What?" My chest tightens. "Why do you need my blood?" I snap my attention to Rhett, who goes to stand beside Dr. Tabb. At that moment, I feel like Hazel when I first saw her—fleeing swift as a hare. But I didn't come all this way to turn tail and run.

Swallowing, I glance at Dr. Tabb's outstretched hand. "Why am I here?"

Dr. Tabb beams. "You are the sole candidate for creating the cure to our little Skinwalker problem. And the key? Your genetic makeup."

I steel myself, crossing my arms across my chest. "Explain."

Dr. Tabb's hand drops and she glances at Rhett with an eyebrow that urges him to speak.

"Remember how Dr. Tabb told us they created the vaccine trials? By extracting the virus from an infected person's blood?" Rhett narrows some of the distance between us. "That person was our ancestral grandmother."

"I've narrowed it down to being carried with the female-linked gene, which is why we are unable to use your brother's blood." Dr. Tabb waves her hands. "But no need to dive into phylogenetics. It is simply that you, Sophie, carry the genetic material of that which created the Skinwalkers..."

"...and therefore, have the capability to destroy them." Rhett reaches out and rests his hands on my shoulders, leveling me with heavy eyes. "We need you Sophie. We need you to help us end the Skinwalkers."