A vicious howl pierces the night, penetrating the walls of the habitat and clawing its way through the interior to where we stand. It's a primal sound made by an apex predator desperate to strip us bare and devour us until nothing remains. But despite the vileness of the alpha's cry, we can't focus on that now. We can't allow the horror to grip our hearts and paralyze us with fear. If Eve and I are to make it out of this alive, we need to move fast and we need to concentrate on what it takes to survive.

Our path lies ahead of us—the main corridor of the Animal Barn.

The people of the first habitat made more progress than Eve and I ever did, but their work didn't last, and neither did they. I assume they came down to Earth as a couple like us, but I have no proof of that. The skeletal remains of livestock fill the enclosures. The decay should stink but doesn't because of the lapsed time. All biological processes have ceased. It's nothing but the bones of farm animals. It's been years since anyone has been here. Maybe longer.

In the semi-darkness, I continue past the cages and turn to the side to find the storage room that Jinx told us about. In an equivalent room in our habitat, Eve had used the 3D printer to make tools for our Animal Barn, which we never put to use. Visible through the gloom, unidentifiable objects lay on the floor, littering the entryway into the storage area with trip hazards. We kick aside a long-handled something, stumbling over it at first, possibly a garden rake used to clean up hay from the enclosures.

I bend over to see what almost tripped me and come up with a shovel. I doubt it will do us any good, so I toss it out of the way.

Another boom rocks the rear airlock door, the alpha wolf using its cranium as a battering ram. The creature's frustrated growls make my insides quiver. Its claws scrape at the doors and drive us to quicken our steps.

Eve backs against the wall, allowing a shaft of meager moonlight to penetrate the polycarbonate roof and make its way to where I stand. I touch her arm for comfort, but it's a shallow gesture at a time like this, and I don't know who benefits from it, her or me.

A bang of screeching metal echoes through the habitat, but the wolf's grumbling complaints haven't breached the passage yet.

My hands fumble over a 3D printer identical to the one Eve used at our hab. I rub my palm over the casing and continue down to a tabletop, feeling for anything that might stand out. My fingers coil around a short-handled tool, and I raise it to check it out. It's a hammer.

"What did Jinx want us to look for in here, anyway?" I say, more to myself than to Eve. "We'll need more than this." I hold up the tool for her to see.

"It had to be weapons. Something to defend ourself with."

I glance up at her. "Right. I assumed that, but what? Where?"

I edge deeper into the room, shifting sideways to let more light inside. It doesn't help much.

My vision has adjusted. Pupils dilated fully.

In the darkness, I make out shapes on the floor and on the counters. "You spent more time in this room than I did. What's in here?"

"I don't know," Eve says. "This isn't our storage area. It's a different hab."

I nod with understanding. There are similarities, but the night could hide subtle differences.

Against the back wall, there's a cabinet with a padlock securing two doors. I pump the hammer up and down, feeling its weight in my hand. It might work. I trod over to the cabinet, draw back my hand like a hatchet, and give it a wallop. The previous inhabitants forged the end of the tool from a composite metal and then chiseled it with the 3D printer. It's not steel, but it's strong enough to break the padlock. Behind the two tall doors, I find four long-stocked items that appear gray in the shadows.

I pull one of them out and toss it to Eve while I search for the required components.

"You found a rifle?!" she says. "Any more in there?"

"Yep, and more than that." I underhand a box of ammo to her.

Eve's eyes bulge. "They were down here long enough to make guns and bullets?"

"I believe they were down here for years before Cain showed up for the first time. There's no telling what else we'll discover. Jinx knew what he wanted us to find in here."

A crack of tortured metal splinters its way toward us. I assume the force of the creature's whaling against the door has sheared off the steel tube holding the wheel-lock on the rear passage, or the bolt itself has broken loose. It's only a matter of time now.

I remove another rifle. I can't tell what kind it is, but from the rounds as big as my forefinger, I estimate it to be the equivalent of a 30-30, powerful enough to put down a deer, and hopefully, strong enough to fell a vile wolf. But I have my doubts.

The rifles come with a magazine holding ten to fifteen rounds. I don't count, I just cram shells in and pull back on a lever on the side. It's not rocket science. I've handled guns before. After my parents passed away in a boating accident, Abraham took me quail hunting to get my mind off things. By that time, I was working at Johnson Space Center in Texas. My parents held out till the last minute and got caught in the flood waters, but Abraham was there for me. We used shotguns that day, but thankfully, he showed me his collection of rifles before we ventured out. He was proud of his collection. We even went deer hunting once. He showed me how to load the weapons and fire them. Safety was a priority, and he always paid attention to details. The focus it took to use a firearm helped distract me from the loss I felt about losing my mom and dad, but I never killed a bird or a deer. I wasn't a great shot.

That better change.

After I get Eve's rifle loaded and give her a crash-course point-and-shoot lesson, we hustle back to the Animal Barn.

"We should lock ourselves inside a cage and shoot at it," Eve says. "That way it can't get to us, and we can kill it."

"But if we can't kill it, we'd find ourselves trapped," I reply. "I have a better idea."

Eve rolls her eyes, but her mouth twists with fear as she tries to play me off. "Spill it then. That thing is coming for us."

"We get up on top of the Animal Barn where it can't reach us."

"How?"

"Easy. I give you a boost, and then you help me up."

"That'll never work."

"Yes. It. Will. It's only about eight feet high, but we need to hurry. Now."

Eve relents and places her boot in the cradle of my hands, and I lift her up where she pulls herself over the top. After I pass her a rifle, I take off down the main corridor, leaving her behind.

"Where are you going?" Her voice shrieks after me like she can pull me back toward her.

"To kill that thing before it gets us."

"But Noah, it'll kill you." She scrambles to the edge of the Animal Barn roof. "Come back!"

"Eve, stay and hide. And don't worry, I'll be back."

With that, I dart down the corridor and tight swing it to the right into the cross passage, racing for the catwalks. I need to get to a hiding place so I can ambush it. I make another hard right down the steel-grated walkway, around to the backside of the animal enclosures, intending to reach the same location where me and Eve jumped over the handrails into the river back at our habitat. My goal is the canal beneath the catwalks.

The waterway runs around the entire middle portion of the habitat, but as soon as I snatch a hold of the top rail, the vile wolf bursts through the airlock door with a resounding crash of fractured metal. The creature's heavy paws pound the floor of the entry hall and then leap across the threshold of the inner door, determined to get to us. As the outline of the wolf's freakishly large body brakes to a halt on the catwalk and peers toward me, I drop over the edge and into the canal.

It's bone dry. The water evaporated long ago.

I brace the rifle stock against my shoulder and aim the barrel up at the catwalk. My heart stammers in my chest as I tread backwards, trying to put space between me and the predator.

The wolf dashes down the walkway, the thunder of its hefty frame clattering the metal grating, shaking it with tremendous force.

Eve screams.

With my rifle, I trace the form of the wolf running in my direction.

I glimpse her figure on the backside of the animal cages, still on the roof, but peering over the edge with her weapon pointing down.

The distraction costs me a split second, but I whip my gun back around as the wolf leaps over the handrail. I squeeze the trigger, twice, lead ricocheting off the top railing.

The creature joins me in the canal, some twenty feet away, and sets its sights on me.

Above me, Eve jostles back and forth, unsure what to do.

The vile wolf charges toward me, its narrowed eyes set above its terrifying jaws.

Eve shoots, sparks flying everywhere as rounds from her gun deflect off the catwalk like hot coals. But it doesn't persuade the wolf to stop or even glance her way. It rumbles forward and then leaps through the air, soaring toward me.

Without thought, my finger clamps down on the trigger, activating the rifle's semi-automatic mode. The thirty caliber rounds blast from the barrel, slamming into the wolf, one after the other, but it keeps flying toward me.

Its paws smash in to me and knock me backwards to the floor of the canal.

I land with the sight of canines chomping toward my face. But as I fall, I thrust my rifle into the wolf's maw, putting the weapon's stock between me and its razor-sharp teeth.

The creature thrashes on top of me, claws digging at either side, but missing my body. Unable to think or breathe, I hold the rifle between me and the wolf—the only thing keeping me alive.

But I can't fend it off forever, and I can't remain this close to its slashing claws and teeth for much longer.

As the wolf pummels me from above, its weight forcing me down, something keeps jabbing into my side. At first, I think it's claws trying to rake open my stomach, but then I remember what it is. With one hand clutching the rifle as the animal presses the stock against my face, its teeth scraping closer and closer with each second, with my other hand, I unlatch the six-inch knife from my waist.

My fingers wrap around the handle and I stab the blade upward, over and over, not sure if I'm hitting anything. But soon, I feel the give and take of the knife striking home in the wolf's abdomen.

Amid what could be my grave, the animal yelps out a wounded whimper and releases its mouth-hold on the stock of my rifle.

As the lights in my head threaten to turn black from the creature's weight on my chest, arms grapple for my shoulders from above. It's then I realize Eve is trying to pull me out from underneath the lifeless body of the vile wolf.

When she yanks me free with my legs and feet pushing for leverage, I fall back into her arms as she collapses against the side of the canal. All I can do is lie here, panting, thankful we're both alive, but deep down, I wonder if there is any hope for us, especially for what comes next—another tortured night on this vile planet we call home.