The next day, the air changed. It wasn’t a smell or a sound but a pressure, as if the entire facility was being squeezed. The lights flickered. People murmured and looked around.

A siren wailed. Red strobes spun. A voice came over the intercom: “All personnel to battle stations. Civilians remain in designated areas. Do not panic. Repeat, do not panic.”

Gunfire echoed from somewhere above. A low rumble followed, like the growl of a giant engine. The floor trembled. Screams seeped down through the concrete. Someone prayed out loud.

I grabbed my brother’s hand and pulled him under the cot. It was no safer there, but it felt less exposed. We waited. Minutes stretched. The sound of fighting grew louder. Something heavy slammed into a wall. Dust drifted down.

A soldier burst into the dormitory, helmet askew, one eye swollen shut. “We’re breached!” he shouted. “They broke through Level Three! Stay back!” He raised his rifle, firing toward the entrance as he backed away. A blur of dark flesh and glistening scales dove through the doorway. It was shaped vaguely like a dog but as big as a car and covered in black armor plates. Its eyes glowed red. Its mouth split wide, revealing rows of jagged teeth. Bullets pinged off its hide. It lunged.

Two men stepped forward. One thrust out his hands, and a wall of ice shot from the floor, slamming into the creature and pinning it against the ceiling. The other man pointed, and arcs of electricity leapt from his fingers, coursing through the beast. It convulsed, screeched, and then lay still, smoke rising from its body. Both men collapsed, blood dripping from their noses.

More creatures poured into the room: horned things with serpentine tails, bloated things that oozed acid, humanoid shapes wreathed in fire. The air filled with the stench of sulfur and rot. People screamed. Some fought back with guns, chairs, fists, whatever they had. Others cowered. Those with abilities—powers we hadn’t had yesterday—stepped forward out of instinct or desperation. A woman’s scream became a sonic blast that shattered a monster’s skull. A teenager’s skin turned to stone as claws raked down his arm. A man reached out and plants erupted from the cracks in the concrete, entangling a demon’s legs.

We were losing. For every monster that fell, two more took its place. The room was filling with bodies, blood, smoke. Through it all, a tall figure in black armor strode. Horns curled back from its head. Purple flames danced in its hands. Its eyes were intelligent. It looked like the demons I had read about in mythology. It raised its arm and hurled a sphere of dark fire toward a group of children. I moved without thinking. My body felt both heavy and light. I saw lines of light connecting everything—the demon’s flame to the air, the ground to the walls. I reached out and pulled on one of the lines.

Time slowed. The fireball’s path bent midair, veering away and exploding harmlessly against the ceiling. A jolt of pain shot through my head. I cried out and fell to my knees.

The demon’s gaze snapped to me. It tilted its head, as if curious, then raised its hand again. Before it could throw another spell, a voice boomed from the intercom: “All civilians proceed to the lower portal chamber now! This is not a drill. Portal activation in ten minutes!”

Soldiers moved through the chaos, shouting, “This way! Move! We’re evacuating!”

“Portal?” I asked.

A soldier grabbed my arm. “It’s our last shot,” he said. “We don’t have time to explain. Get moving!”