The system

Tessa's eyes snapped open, and there was nothing human left behind them.

"Back!" Nooh shouted.

Amelia threw herself sideways, but Tessa's hand shot out and caught her arm. Her nails tore through Amelia's sleeve and dug into her skin. Amelia screamed, kicking against the floor as she tried to pull free.

"Let go of her!" Chloe grabbed Amelia around the waist and hauled her backward with everything she had. The sleeve ripped, and Amelia fell onto her back. Chloe landed beside her, gasping.

Tessa rose from the tiles with a strange, jerking movement. Her head hung at an unnatural angle, and a wet, rattling sound hissed from her throat.

"Tessa," Amelia gasped, clutching her bleeding arm. "It's me. I'm Dr. Carter."

"She can't hear you!" Ethen backed away so quickly that he tripped over a drip stand. "She's gone! She's gone!"

"She was talking to me ten seconds ago!"

"That was ten seconds ago!"

Tessa lunged.

Nooh stepped in front of her, gripping a metal stool with both hands. He drove its legs into her chest, forcing her back against the desk. Tessa fought against it, her teeth snapping as Nooh pressed harder. His arms began to tremble.

"I can't hold her much longer," he said, his voice frighteningly calm. "Someone needs to do something."

"Do what?!" Chloe cried. "She's a nurse! She's twenty-three!"

Nooh's jaw tightened. "She was."

"Don't say that!"

Tessa snapped her teeth an inch from Nooh's face. He jerked his head back but kept pushing the stool against her.

Amelia crawled onto her knees. Her arm burned where Tessa's nails had torn through it. Blood ran down her wrist and dripped onto the white floor.

Her lungs seized. The smell of blood warm, coppery, almost sweet pulled her back to the kitchen tiles. Her mother's hand reaching out. The terrible silence afterward.

No. Not now. Please.

"Amelia?" Chloe shook her shoulder. "You're bleeding. Look at me, not the floor. Look at me!"

"I can't breathe."

"Yes, you can. In through your nose. Come on, breathe with me."

"I can't."

"Dr. Carter!" Ethen shouted from across the room. "Do something! You're the doctor!"

I'm not a doctor.

Amelia's eyes filled with tears. I'm a nine-year-old girl standing in a kitchen.

Then the air in front of her flickered. A pale blue panel appeared out of nowhere, floating directly in her line of sight. Thin white letters covered it. She blinked, but the panel remained.

MEDICAL SURVIVAL SYSTEM ACTIVATED.

Amelia stared at it, unable to move.

"Chloe," she whispered. "Can you see that?"

"See what?" Chloe glanced around. "Amelia, there's nothing there. You're in shock. Just breathe."

"There's writing."

"Oh God," Ethen groaned, sliding down the wall. "She's lost it too."

The letters shifted.

HOST: AMELIA CARTER.

STATUS: HIGH STRESS.

HEART RATE: 168 BPM.

SURVIVAL RATING: LOW.

"Low," Amelia muttered. "Great. Thanks."

Chloe looked at her in alarm. "Who are you talking to?"

"Nobody. Just give me a second."

New lines appeared.

YOU HAVE BEEN CHOSEN TO TREAT THE WOUNDED. MISSIONS, SKILLS, AND SUPPLIES ARE NOW AVAILABLE.

THIS SYSTEM WILL NOT SAVE YOU. YOU MUST SAVE YOURSELF.

A small grey box appeared at the bottom, labeled INVENTORY. It was completely empty.

"Of course it's empty," Amelia breathed.

"Nooh, I need help!" Nooh grunted. Tessa was pushing harder, and one of the stool's metal legs had begun to bend. "This won't hold!"

Amelia forced herself to stand, gripping the edge of the bed. Her legs felt weak, but she made them move.

The blue panel flashed again.

MISSION 1: SURVIVE THE NEXT TEN MINUTES.

REWARD: BASIC TREATMENT KIT.

"Ten minutes," Amelia said aloud. "It wants me to survive ten minutes."

"What did you want to do?!" Chloe shouted.

"I'll explain later!" Amelia glanced toward the ward doors. "Hayes. Where's Hayes?"

"He went to the station to write orders," Chloe said. "That was ages ago."

"Then he's either dead or he ran."

"Or he's hiding like me," Ethen muttered.

"Ethen, so help me…"

A sharp crack interrupted her. One of the stool legs snapped clean off.

Tessa broke free and crashed forward. Nooh dropped the broken stool and seized her wrists, struggling to keep her teeth away from his shoulder.

"Amelia!" he roared. "A sedative! Anything!"

"I don't have time to draw it up!"

"Then find it faster!"

Amelia scrambled to the medical cart and yanked open the top drawer. Gauze, tape, alcohol swabs, and three glass vials rattled inside. She grabbed the vials and squinted at their labels.

"Midazolam," she said. "It can sedate her."

"Can?" Chloe shouted.

"I don't know how she'll respond!"

Amelia's fingers shook as she reached for a syringe. Before she could draw up the medication, the blue panel appeared above the cart.

NEW SKILL AVAILABLE: EMERGENCY DOSAGE ASSESSMENT.

ACTIVATE? YES / NO.

Amelia didn't hesitate. "Yes!"

The panel brightened, and a new message appeared beneath it.

SYSTEM-ASSISTED DOSAGE CALCULATION ACTIVE.

RECOMMENDED DOSE: 10 MG.

ROUTE: INTRAMUSCULAR.

TARGET: LARGE MUSCLE.

Amelia stared at the number. The system was guiding her, but she still had to make the injection herself.

"Ten milligrams," she said. "Chloe, syringe!"

Chloe shoved one into her hand. Amelia drew up the medication, her movements steadier now. The fear hadn't disappeared. It was still twisting in her stomach, but the system's guidance gave her something to focus on.

"Nooh, hold her still!"

"I'm trying!"

Amelia circled behind Tessa and drove the needle into the muscle of her thigh, pressing the plunger down.

Tessa shrieked and twisted violently. Her arm swung back, striking Amelia across the face. Amelia crashed onto her hip, pain shooting up her side.

"Amelia!" Chloe screamed.

"I'm fine!" Amelia winced. "I'm okay!"

Tessa staggered, still fighting Nooh. Her movements didn't stop at once. She thrashed against him, her teeth snapping as he struggled to keep her away.

Then, slowly, her strength began to fade. Her knees buckled. Nooh released her wrists and stepped back just as she collapsed onto the floor.

Silence fell over the room. Nobody dared to breathe.

"Is she asleep?" Chloe whispered.

Nooh crouched beside Tessa and checked her pulse. "Not asleep. Her heart's still beating, but it's slow."

"So she's alive?" Chloe asked.

Nooh looked at Tessa's grey skin and the dark lines spreading beneath it. "I don't know what she is."

A line of light rolled across the floating screen.

MISSION UPDATE: 8 MINUTES REMAINING.

BASIC TREATMENT KIT WILL BE AWARDED UPON COMPLETION.

"Great," Amelia muttered, pushing herself upright with one hand against her sore hip. "So there's more."

"More what?" Ethen asked, his voice trembling.

"More of them. We need to move. All of us. Right now."

"Where?!"

"I don't know yet!"

A loud BANG shook the double doors at the end of the ward. They slammed against their frame, then took another hit. Dozens of heavy fists pounded against the other side.

The overhead lights flickered. Chloe grabbed Amelia's arm, her knuckles white.

"Those doors won't hold," she whispered.

Another message flashed across the blue panel, glowing red.

WARNING: 11 INFECTED APPROACHING.

AVAILABLE EXIT ROUTES: 1.

A sharp crack rang through the ward. A thin fracture spread across the heavy glass in the doors.