Clean Nails
title: "The Immunity Ward" wordCount: 2258
The blood on the medical wing floor is fresh enough to smear under Cass's boot, and the handprint on the wall is too small to be an adult's.
She froze. The stolen credentials dangled from her neck on a lanyard that didn't belong to her—Dr. Helena Voss, Immunology Research, Level 4 clearance. The real Dr. Voss was probably still unconscious in the supply closet three floors down, zip-tied and gagged with her own lab coat. Cass had ninety minutes before the shift change. Maybe less if someone found her.
The handprint was at hip height. Small fingers splayed wide, reaching for something or pushing away. The blood trail led deeper into the corridor, past doors marked with biohazard symbols and warnings about spore exposure protocols.
Her chest tightened. Each breath scraped like metal filings in her lungs.
The maintenance tunnels had been worse—narrow passages thick with condensation and the sweet-rot smell of mycelium breaking down organic matter in the ventilation system. She'd crawled through two hundred meters of that darkness, following the blueprints Finn had pulled from the city archives. He'd wanted to come with her. She'd told him to stay with Mara, keep her hidden, keep her safe.
She hadn't told him she was coming here.
The corridor branched. Left toward the isolation chambers, right toward the research labs. The blood went left.
Cass followed.
Her fingers found Eli's dog tags through her shirt. The metal was warm from her skin. She pressed them hard enough to hurt.
The isolation wing was quieter than it should be. No footsteps, no voices, no hum of medical equipment. Just the low thrum of air filtration and the occasional hiss of pressure seals. The walls were newer here, reinforced polymer instead of concrete. Observation windows every ten meters, thick glass with wire mesh embedded inside.
The first three chambers were empty. Beds stripped, floors scrubbed clean, no sign anyone had been there recently.
The fourth chamber had someone in it.
Cass's hand went to the knife at her belt before she recognized the profile. Dark hair pulled back, shoulders hunched forward, sitting on the edge of the bed like she was waiting for something.
Mara.
Not strapped down. Not sedated. Not even locked in—the door control showed green, unsealed.
Cass's pulse hammered in her throat. She moved to the observation window, pressed close enough that her breath fogged the glass.
Mara looked healthy. Better than healthy. Her skin had color, her movements were steady, and when she stood to pace the small room, there was no tremor in her hands. No cough. No visible signs of spore exposure or infection.
A researcher entered the chamber. White coat, tablet in hand, speaking to Mara like they were colleagues discussing data. Mara nodded, gestured to her arm where an IV port was taped in place. The researcher made notes. Mara smiled.
The floor tilted under Cass's feet.
She'd expected restraints. Expected fear. Expected Mara to be another victim of whatever the Council was doing in this place.
The researcher left. Mara sat back down, picked up a book from the bedside table, and started reading.
Cass's hand was on the door control before she'd decided to move.
The chamber door slid open with a soft pneumatic hiss.
Mara's head snapped up. The book fell from her hands. "Cass?"
"Get up." Cass's voice came out rougher than she'd intended. "We're leaving."
"What are you—" Mara stood, but she didn't move toward the door. "You can't be here."
"Neither should you." Cass stepped inside, letting the door seal behind her. The air in the chamber was cooler, filtered, tasting of nothing. "What the hell is this?"
"It's complicated."
"Try me."
Mara's mouth went flat. She looked older than she had three days ago, or maybe Cass was just seeing her clearly for the first time. The lines around her eyes. The careful way she held herself, like someone who'd learned to measure every movement.
"I'm helping them," Mara said.
"Helping who?"
"The research team. The Council." Mara's hands twisted together. "They're studying immunity markers. People who've been exposed to high spore concentrations but haven't developed infections. I'm one of them."
Cass's chest ached. She forced herself to breathe through it. "You're a test subject."
"I'm a collaborator." Mara's chin lifted. "There's a difference."
"Is there."
"Yes." The word came out sharp. "I chose this. They offered me protection—real protection, not just hiding in tunnels hoping the Council doesn't find us. My family gets medical care, housing in the clean zones, food that isn't rationed. All I have to do is let them study my blood, my tissue samples, run their tests."
"And what do they get?"
"Data." Mara moved to the window, staring out at the corridor. "Information about how some people's immune systems adapt to spore exposure. It could save lives, Cass. Real research, not just survival."
"Whose lives." Cass's hand found the dog tags again. "The Council's? The people who can afford whatever treatment they develop from your blood?"
"Everyone's." But Mara's voice wavered. "Eventually."
"That's surface thinking."
Mara turned. Her eyes were hard. "Don't. Don't come in here and judge me for making the choice that keeps my daughter alive."
The words hit like a fist. Cass had forgotten about Mara's daughter. Seven years old, living in the outer districts with Mara's sister. Or she had been.
"Where is she now?" Cass asked.
"Safe." Mara's shoulders dropped. "In a Council housing unit. Clean air, clean water, school. Things I couldn't give her before."
"And all you had to do was sell yourself."
"All I had to do was survive." Mara's voice cracked. "Something you might want to consider, given how you sound right now. When's the last time you slept? When's the last time you could take a full breath without it hurting?"
Cass said nothing.
"That's what I thought." Mara crossed her arms. "You're dying, Cass. We both know it. And you're still out here trying to save people who don't want to be saved."
"You accessed classified files." Cass kept her voice level. "The Council knows. They're hunting whoever broke into the Myco-Farm databases."
"I know." Mara's expression didn't change. "That's why I came here. That's why I made the deal."
"You traded information for protection."
"I traded my cooperation for my family's safety." Mara stepped closer. "There's a difference."
"Not to the people you sold out."
Mara's hand moved fast, catching Cass's wrist before she could pull away. Her grip was strong, steady. "I didn't sell anyone out. I gave them data they would have found eventually anyway. And in exchange, my daughter gets to live past her tenth birthday."
"What about Eli?" The question came out before Cass could stop it. "Did he get that choice?"
Mara's grip loosened. She stepped back, and something in her face shifted. Not guilt, exactly. Something colder.
"What about him?" Mara asked.
"You knew." Cass's throat felt tight. "You knew he was investigating something. You knew it was dangerous."
"Yes."
The admission was worse than a lie would have been.
"And you didn't warn him," Cass said.
"No."
"Why."
Mara's hands clenched at her sides. "Because I had my own family to protect. Because Eli was always going to dig until he found something that got him killed. Because I couldn't save him and save my daughter, and I chose her."
The air in the chamber felt too thin. Cass's vision narrowed to Mara's face, to the set of her jaw, to the absence of apology in her eyes.
"He trusted you," Cass said.
"I know."
"He would have helped you. If you'd asked."
"I know that too." Mara's voice was steady. "But helping me would have meant putting himself at risk, and I wasn't going to let him make that choice. So I made it for him."
"By letting him die."
"By letting him be himself." Mara's eyes were dry. "Eli was never going to stop. You know that. He was going to keep pushing until something pushed back harder. I just made sure it wasn't my problem when it happened."
Cass's hand was on her knife before she'd thought about it. The blade cleared the sheath, and Mara didn't flinch.
"Go ahead," Mara said. "If it'll make you feel better."
It wouldn't. Cass knew that. Knew it the way she knew her own heartbeat, irregular and struggling. She slid the knife back into its sheath.
"I came here to help you," Cass said.
"I don't need help." Mara's voice was gentle now, which was worse. "I need you to leave before you ruin the only good thing I've managed to build out of this mess."
"The Council is using you."
"Everyone uses everyone." Mara moved to the door control. "That's how survival works. You trade what you have for what you need, and you hope the deal holds long enough to matter."
"And when it doesn't?"
"Then you make a new deal." Mara's finger hovered over the control. "Go home, Cass. Go back to Finn. Figure out how to save yourself instead of trying to save people who've already made their choices."
The door slid open.
An alarm shrieked through the corridor.
The sound was wrong—not the steady pulse of a security breach, but a rapid, escalating wail that meant containment failure. Red lights strobed along the ceiling. The air pressure shifted, and Cass's ears popped.
"Spore breach." Mara's face went pale. "Adjacent sector."
"Where?"
"Doesn't matter." Mara grabbed Cass's arm, pulling her into the corridor. "The whole wing will seal in ninety seconds. We need to move."
They ran. Cass's lungs burned, each breath a knife between her ribs. The corridor branched and branched again, and Mara navigated without hesitation, pulling them toward the emergency exits.
Other people appeared—researchers in white coats, security personnel, all moving in the same direction. No one questioned Cass's presence. No one looked at her stolen credentials. They just ran.
The emergency exit was ahead, a reinforced door with a manual release bar. Twenty meters. Fifteen.
"Wait." Cass pulled against Mara's grip. "Your daughter. Where is she?"
"Not here." Mara didn't slow down. "She's in the residential sector. She's safe."
"You don't know that."
"I know the Council doesn't breach containment in residential areas." Mara's voice was hard. "They're not stupid. They'll seal this wing and vent it if they have to, but they won't risk the clean zones."
Ten meters.
"Come with me," Cass said.
"No."
"Mara—"
"I can't." Mara stopped, and Cass nearly crashed into her. "If I leave now, the deal breaks. They'll revoke my family's protection. My daughter goes back to the outer districts, back to rationed air and contaminated water and a life expectancy of maybe thirty years if she's lucky."
"You can't save everyone." The words came out desperate. "Eli couldn't either."
Mara's expression cracked. Just for a second, just enough to show the fear underneath. "I know. But I can save her. That has to be enough."
The alarm changed pitch. A recorded voice echoed through the corridor: "Containment seal initiating in thirty seconds. All personnel evacuate immediately."
"Go." Mara pushed Cass toward the exit. "Please."
Cass's hand closed around Mara's wrist. "Not without you."
"Cass—"
"I don't care about your deal." Cass pulled, and Mara stumbled forward. "I don't care about the Council's protection. You're coming with me."
"You're going to get us both killed."
"Maybe." Cass's grip tightened. "But at least you'll die making your own choice instead of theirs."
They reached the exit. Cass slammed her palm against the release bar.
Nothing happened.
She hit it again. The bar moved, the mechanism clicked, but the door stayed sealed.
"Twenty seconds," the recorded voice said.
"It's locked." Mara's voice was flat. "They've already initiated the seal protocol. Nothing opens until containment is verified."
Cass looked back down the corridor. The other personnel had disappeared into side passages, emergency shelters, anywhere but here. The red lights painted everything in shades of blood.
"There has to be another way out," Cass said.
"There isn't." Mara leaned against the wall, and for the first time since Cass had found her, she looked tired. "This is it. This is what happens when you try to save people who don't want to be saved."
"Shut up." Cass examined the door mechanism, looking for a manual override, a weak point, anything. Her fingers found the seam where the door met the frame. Solid. Reinforced. Built to contain spore breaches and everything else.
"Ten seconds."
Eli's voice in her memory: Sometimes the only way out is through.
But there was no through here. Just a sealed door and a contaminated wing and choices that had already been made.
Cass's hand found the dog tags again. The metal was cold now.
"I'm sorry," Mara said quietly. "About Eli. About all of it."
"Don't." Cass's throat was tight. "Don't apologize now."
"When else would I do it?"
The alarm cut off. The silence was worse.
Then a new sound—hydraulic pressure releasing, locks disengaging. But not the emergency exit. The door behind them, the one leading back into the medical wing.
Cass turned.
The door slid open. A figure stood in the doorway, backlit by the corridor lights. Tall, composed, hands clasped in front of her like she was attending a council meeting instead of a containment breach.
Vera Latch.
"Cass." Her voice was soft, measured, carrying easily in the sudden quiet. "We need to talk about your brother—the one who's still breathing."
The emergency exit sealed shut with a hydraulic hiss.