Elena woke to the sound of urgent knocking. Checking her watch—5:17 AM—she opened the door to find Eva, tears streaming down her small face.

  "Miss Elena," the little girl sobbed, "Adam won't wake up. He's burning hot."

  Elena grabbed her medical bag. "Get Viktor," she told Eva, already moving toward the children's quarters.

  Adam y on his cot, his skin flushed and radiating heat. Elena's practiced fingers found his pulse—too rapid, too weak. His breathing came in short, bored gasps.

  "104.3," she murmured, reading the thermometer. "Much worse than yesterday."

  Viktor appeared in the doorway, concern etched across his features. Eva clung to his hand, her eyes wide with fear.

  "He was okay before bed," Eva insisted. "Just a little warm."

  Elena's examination was methodical despite her growing arm. "Lymph nodes severely swollen. Unusual rash pattern developing on his neck."

  Viktor moved closer, his enhanced senses detecting subtle details invisible to Elena—the specific scent of the child's sweat, the faint discoloration beneath his fingernails, the barely perceptible tremor in his muscles.

  "Can I speak with you outside?" Viktor asked quietly.

  In the corridor, safely out of Eva's hearing, he kept his voice low. "These symptoms... I've seen them before."

  Elena's face paled. "The virus?"

  "These symptoms... they resemble a side effect we observed in our immortality research." He ran a hand through his hair. "Some test subjects developed this exact pattern when the regenerative compounds interacted with their immune systems. Before everything went wrong, we were trying to understand why some recovered while others developed more severe reactions."

  "What treatments worked?" Elena asked, her mind already racing through pharmaceutical options.

  "That's the problem. Conventional antivirals were ineffective." He hesitated. "There was one thing, though. It wasn't in the official protocols."

  Elena understood immediately. "Blood. Your blood."

  Viktor nodded. "In minute quantities. The regenerative properties seem to counter the virus without triggering transformation if the dose is extremely small."

  "That's incredibly risky," Elena said, though her tone was considering rather than dismissive. "How can you be certain about dosage?"

  "I can't be completely certain," Viktor admitted. "But I've calcuted based on body weight and observed effectiveness rates from the b data. One drop, heavily diluted, administered orally."

  They stood in silence, the weight of the decision pressing on them. From inside the room, they heard Eva's soft voice singing to her brother—a lulby their mother had taught them before the outbreak.

  "If we do nothing," Elena said finally, "what happens?"

  "Best case, severe illness for weeks. Worst case..." Viktor didn't finish the sentence.

  Elena took a deep breath. "What do you need?"

  "Sterilized container, distilled water, dropper, and privacy."

  While Elena gathered supplies from the medical storage, Viktor sat with the twins, telling Eva stories to distract her from her brother's bored breathing. When Elena returned, they implemented their hastily-devised pn.

  "Eva," Elena said gently, "could you fetch us more cool water for Adam's forehead?"

  Once the girl left with the empty basin, Viktor quickly pricked his finger with a sterilized needle. A single drop of deep crimson blood welled up, which he allowed to fall into the vial of distilled water Elena held ready. The blood dispersed, turning the solution pale pink.

  "It needs to be administered immediately," Viktor said. "The properties degrade rapidly after extraction."

  Elena filled the dropper, her hands steady despite her racing heart. "Eva will be back any moment."

  Viktor carefully lifted Adam's head while Elena pced three drops of the diluted solution on the boy's tongue. They had just returned him to his original position when Eva returned, water sloshing in the basin she carried carefully between small hands.

  "Will he be okay?" she asked, her voice small.

  Elena squeezed her shoulder. "We're doing everything we can. The medicine needs time to work."

  They maintained a constant vigil, Viktor and Elena taking turns monitoring Adam's vital signs. Within two hours, his fever had dropped to 102.1. By noon, his breathing had eased, and the angry rash had begun to fade.

  "His lymph nodes are less swollen," Elena noted, carefully documenting each improvement in her journal while keeping her observations clinical for any potential readers. "Fever continuing to decrease at unexpected rate."

  Viktor kept his expression neutral, though relief coursed through him. "The experimental antiviral compound appears effective."

  By evening, Adam was awake, weak but alert, asking for water. Eva refused to leave his side, reading him stories from a tattered book they'd found in the Underground's small library.

  "It's remarkable," Elena said softly to Viktor as they observed the children from the doorway. "I've never seen such rapid recovery from systemic infmmation."

  "Indeed," came Professor Chen's voice from behind them. They turned to find Sophia approaching, her sharp eyes moving from them to the recovering child. "I heard Adam's condition had improved dramatically."

  "Yes," Elena said, maintaining her composure. "The fever broke this afternoon."

  Sophia moved past them to Adam's bedside, her examination thorough and methodical. "Yesterday he could barely sit up. Today his markers are almost normal." She gnced at Elena's notes. "What treatment did you administer?"

  "A compounded antiviral based on some research I recalled from my university days," Elena replied, the half-truth coming easily. "Experimental, but his condition was deteriorating rapidly."

  "I'd be interested in the formu," Sophia said, her tone making it less request than demand.

  "Of course," Elena nodded. "I'll reconstruct it from my notes when—"

  Her words were cut short by a sudden darkness as the lights throughout the medical section flickered and died. Emergency voices called out from the adjacent treatment area.

  "Generator's failed again," someone shouted. "Backup systems not responding!"

  "Critical patient in Bay Three!" called a panicked voice. "Ventitor's down!"

  Viktor moved instinctively, navigating the pitch-bck room without hesitation. While others stumbled and collided in the darkness, he strode directly to Bay Three, where the sound of gasping breaths guided his enhanced senses.

  "Manual respiration," he called calmly, his hands finding the equipment with perfect precision despite the complete darkness. His fingers located the manual override, disconnected the power-dependent system, and attached the hand pump. He began rhythmic compressions, maintaining exactly the right pressure and frequency.

  "How can you see what you're doing?" came Sophia's voice, much closer than he'd realized.

  Before he could formute a response, the emergency lights flickered on, casting the room in dim red illumination. Viktor found Sophia standing directly beside him, her eyes no longer curious but calcuting as she observed his hands perfectly positioned on equipment he shouldn't have been able to locate in complete darkness.

  "Excellent spatial memory," he offered weakly.

  "And exceptional night vision," she countered, watching him with newfound intensity. "And remarkable hearing to locate the patient's exact position."

  The main lights surged back to life, illuminating the full medical section. The crisis passed as quickly as it had begun, with the generator humming back to life and automated systems resuming normal function.

  Viktor retreated from the patient's bedside, aware of Sophia's gaze following his every movement. When their eyes met across the room, he saw the moment when certainty repced suspicion in her expression.

  She knew.

  Later, as Viktor checked on Adam once more before the night shift, he found the boy sleeping peacefully, his color normal, breathing steady. Eva had finally succumbed to exhaustion herself, curled beside her brother on the narrow cot.

  "You saved him," Elena whispered, joining Viktor at the doorway. "But at what cost?"

  Viktor watched Sophia across the common area, her eyes never leaving him as she made notes in a small journal. "We'll know soon enough," he murmured.

  In the softest voice, meant only for Elena's ears, he added, "We may need to prepare for a hasty departure."

  Elena's fingers brushed against his, a momentary touch of solidarity. "I'll start packing emergency supplies. Discretely."

  As they walked away from the children's quarters, Sophia continued watching, her gaze calcuting, measuring, and most dangerous of all—curious.