The Siphoner outpost was a cathedral of blood.

  Elias had seen many things in the Tower, organic tunnels that pulsed with alien life, creatures that defied medical understanding, horrors that would haunt his dreams for years to come. But nothing had prepared him for the sight that greeted them as they crossed the threshold into Floor 15.

  The chamber was vast, carved from the Tower's living tissue but transformed by human hands into something deliberately sacred. Red banners hung from organic protrusions along the walls, their fabric stained with what could only be dried blood, symbols embroidered in darker crimson depicting stylized hearts and spiraling vessels. The air was thick with the copper scent of fresh blood, so concentrated that Elias could taste it on his tongue.

  At the center of the chamber stood the blood vats.

  Three massive containers, each the size of a small vehicle, filled with liquid that glowed faintly in the dim light. The vats were connected to the Tower's walls by thick tubes—organic conduits that pulsed rhythmically, feeding the containers with a constant supply of the Tower's own circulatory fluid. Climbers' blood, mixed with the Tower's, creating something that was neither fully human nor fully alien.

  Around the vats, Capillaries moved with ritualistic precision. Dozens of them, all wearing the red cloaks that marked them as low-ranking Siphoners, performing tasks that seemed equal parts practical and ceremonial. Some tended the tubes, adjusting flow rates and checking connections. Others knelt before the vats in prayer, their lips moving in the same chanting rhythm that had echoed through the gate.

  And everywhere, on the walls, on the floor, on makeshift altars scattered throughout the chamber, were offerings. Small containers of blood, arranged in patterns that suggested religious significance. Tokens and trinkets left by supplicants. The dried remains of creatures Elias didn't recognize, their husks arranged in poses of supplication.

  "This is insane," Mira whispered beside him, her hand tight on her knife. "They've built a church. A church to blood."

  "The Vineyard," Elias murmured, remembering Old Tom's warnings. "This is what it looks like from the inside."

  Lira pressed close to him, her ghostly form flickering with distress. "Papa, they all feel wrong. Every single one of them. Empty inside, like something's been taken."

  Before Elias could respond, a shout rang out across the chamber.

  "Intruders!"

  The word echoed through the space, and suddenly every Capillary in the chamber was looking at them. Dozens of faces, pale and hollow-eyed, turned toward the entrance where Elias, Mira, and Lira stood frozen.

  They'd been spotted the moment they crossed the threshold. There was no hiding, no retreating, the gate behind them was already blocked by figures that had materialized from the shadows, cutting off any escape.

  Within seconds, they were surrounded.

  Capillaries closed in from all directions, their movements coordinated with eerie precision. They didn't attack, not yet—but their intent was clear. Escape was impossible. Resistance was futile.

  "Weapons down," a voice commanded from within the crowd. "Hands where we can see them."

  Elias considered his options. His vitality was still dangerously low, his body exhausted from the gauntlet of Floor 14. Mira was in even worse shape, her wounds barely closed, her strength flagging. They could fight—they would fight, if it came to that, but against this many opponents, in this condition, the outcome was certain.

  He lowered his spear slowly, setting it on the ground.

  "Elias," Mira hissed. "What are you doing?"

  "Surviving." He met her eyes. "Trust me."

  She held his gaze for a long moment, then cursed under her breath and dropped her knife.

  The Capillaries moved in immediately, securing their weapons, binding their hands with lengths of organic cord that felt disturbingly like dried sinew. They weren't gentle, but they weren't unnecessarily brutal either—professional, efficient, like soldiers following protocol.

  "Bring them to the center," the same voice commanded. "Brother Sero will want to see them."

  They were pushed forward through the crowd, the Capillaries parting to create a path toward the blood vats. Elias kept his head up, his eyes moving constantly, cataloging details—the number of guards, the layout of the chamber, potential exits, anything that might be useful if negotiation failed.

  The center of the chamber was dominated by a raised platform, positioned between the three blood vats like a stage before an audience. Upon the platform stood a single figure, his back to the approaching prisoners, his attention focused on one of the vats.

  He was tall, taller than any Climber Elias had seen, his frame stretched and gaunt as if the Tower itself had pulled him toward the ceiling. His robes were darker than the Capillaries', a deep crimson that was almost black, and his hands—visible where they emerged from his sleeves—were marked with ritual scars that formed intricate patterns across his skin.

  Brother Sero.

  The Siphoner leader turned as they were brought before the platform, and Elias got his first clear look at the man's face.

  It was a face that had once been handsome, perhaps, but was now something else entirely. The features were sharp, almost emaciated, with cheekbones that stood out like blades beneath paper-thin skin. His eyes were the most striking feature, pale blue, almost colorless, and utterly calm. They held no malice, no cruelty, no passion of any kind. They were the eyes of a man who had moved beyond such trivial concerns.

  "The medic," Sero said, his voice soft and resonant, carrying easily through the chamber despite its quiet tone. "I've heard about you."

  Elias felt a chill run down his spine. "From Kael?"

  "Among others." Sero descended from the platform, his movements fluid and unhurried. He approached Elias with the casual confidence of a predator who knew its prey couldn't escape. "You've caused quite a stir, Doctor Thorne. A man who heals in a place built on bleeding. A father carrying his daughter's ghost. A Climber who refuses to play by the Tower's rules."

  He stopped an arm's length from Elias, those pale eyes examining him with clinical interest.

  "I confess, I'm curious about you."

  "The feeling isn't mutual," Elias replied flatly.

  Sero smiled, a thin expression that didn't reach his eyes. "Defiance. How refreshing." He circled Elias slowly, studying him from different angles. "Most Climbers who stand before me are either terrified or pleading. You're neither. Why is that?"

  "Because I've already died once. Everything after that is borrowed time."

  The smile widened slightly. "A fatalist. How disappointing. I had hoped for something more... philosophical."

  He completed his circuit, returning to face Elias directly. His gaze shifted briefly to Mira, then to Lira's hovering form, before settling back on Elias.

  "Tell me, Doctor. Do you know why we call ourselves the Vineyard?"

  Elias said nothing.

  "Because blood is life," Sero continued, his voice taking on a preaching cadence. "The Tower teaches us this truth with every breath we take. Blood is the currency of survival, the fuel that powers our abilities, the essence that separates the living from the dead. The Tower demands blood, and we provide it."

  He gestured toward the blood vats, the massive containers pulsing with their crimson contents.

  "Most Climbers see this as cruelty. They resent the Tower's hunger, fight against its demands, climb its floors as if they were escaping a prison. But we understand the truth. The Tower isn't our prison, it's our teacher. And blood isn't a burden, it's a sacrament."

  "You drain people dry and call it religion," Mira spat. "That's not philosophy. That's murder with better marketing."

  Sero turned to her, his expression unchanged. "Is it? When a doctor takes blood for a transfusion, is that murder? When a farmer slaughters livestock for food, is that cruelty? The Tower has needs, and we serve those needs. In return, the Tower rewards us with power, with purpose, with a place in its grand design."

  "The people you drain don't volunteer," Elias said. "That's the difference."

  "Some do." Sero's pale eyes glittered. "You'd be surprised how many Climbers come to us willingly, offering their blood in exchange for protection, for passage, for the simple comfort of belonging to something larger than themselves. The Vineyard provides community in a place designed to isolate. We offer meaning in a world stripped of it."

  He paused, letting the words settle.

  "But you're right—not everyone volunteers. Some resist. Some fight. And for those..." He spread his scarred hands. "We take what's needed. The Tower demands it. We are merely its instruments."

  Elias studied the man before him, trying to reconcile the calm philosophy with the horror of what the Vineyard represented. Brother Sero wasn't ranting or raving. He wasn't a madman drunk on power. He was something far more dangerous, a true believer, utterly convinced of his own righteousness.

  "What do you want from us?" Elias asked.

  "Straight to business." Sero nodded approvingly. "I appreciate directness. Very well." He clasped his hands before him, the ritual scars forming patterns that seemed to shift in the dim light. "You wish to pass through our territory. To continue climbing. This is understandable, everyone wishes to climb. But passage through the Vineyard is not free."

  Stolen story; please report.

  "How much?"

  "Eight liters."

  The number hit Elias like a physical blow. Eight liters. More blood than a human body contained. More than he currently had in reserve. A price designed to be impossible—or to require sacrifice.

  "That's a death sentence," Mira said. "You know we can't pay that."

  "Can't you?" Sero's gaze moved to Lira, to the ghostly girl hovering beside Elias. "Your daughter is connected to your blood, Doctor. I can sense it—the bond between you, the way her existence draws from your vitality. She is, in a very real sense, a vessel for your blood. If you were to... release her..."

  "No." The word came out hard, absolute.

  "The Tower would reclaim what she holds. Combined with your current reserves, it would easily meet our price. Your passage would be guaranteed. You and your companion could continue climbing, unburdened by—"

  "I said no."

  Sero raised an eyebrow. "You would choose a ghost over your own survival?"

  "She's my daughter."

  "She's already dead, Doctor. What you're carrying is a memory given form. A beautiful memory, certainly, but a memory nonetheless. Is it worth dying for?"

  Elias met those pale, colorless eyes without flinching. "Yes."

  A long silence stretched between them. Sero studied Elias with something that might have been respect, or might have been pity—it was impossible to tell with those empty eyes.

  "Then we have a problem," the Siphoner leader said finally. "You cannot pay our price. You will not sacrifice what's required. And I cannot allow Climbers to pass through our territory without tribute—it would undermine everything the Vineyard stands for."

  "Then we fight," Mira said, her voice resigned. "And we die. Is that what you want?"

  "What I want is irrelevant. The Tower's needs are all that matter." Sero turned away, ascending the platform once more. "You will be held until morning. Then you will be drained—slowly, so as not to waste any—and your blood will join the vats. Your bodies will be returned to the Tower's tissue. Your daughter..." He glanced at Lira. "She will fade on her own, once your blood no longer sustains her."

  "Wait."

  The word came from Elias, sharp and urgent. Sero paused, looking back over his shoulder.

  "You said the Vineyard provides community," Elias continued. "Protection. That means you have members who get hurt. Members who need healing."

  Sero turned fully, interest flickering in those pale eyes. "Go on."

  "I'm a doctor. A trauma surgeon. I've spent twenty years keeping people alive in situations where they should have died." Elias stepped forward, as far as his bonds would allow. "You have wounded Siphoners—I can see them from here. The ones lying near the far wall, being tended by your Capillaries. They're dying. I can tell by the way they're breathing, by the pallor of their skin. Whatever treatment your people are providing, it isn't working."

  Sero's expression didn't change, but his attention sharpened. "You're observant."

  "I'm trained. And I'm offering you a trade." Elias met the Siphoner leader's gaze steadily. "Let me treat your wounded. If I can save them—if I can do what your healers cannot—you grant us passage. No blood payment. No sacrifice."

  "You would heal your enemies?"

  The question hung in the air, loaded with implication. Elias thought about all the people he'd treated over the years—soldiers who'd done terrible things, criminals brought in from prison, patients whose beliefs and actions he found repugnant. He'd healed them all, because that was what doctors did. The Hippocratic oath didn't include exceptions for personal morality.

  "I'm a medic," Elias said simply. "It's what I do."

  Sero descended from the platform once more, approaching Elias with renewed interest. "And if you fail? If your patients die despite your efforts?"

  "Then we pay your original price. Eight liters. Drain us dry."

  "Elias," Mira hissed. "What are you doing?"

  "Negotiating," he replied without looking at her. His attention remained fixed on Sero, watching for any sign of acceptance or rejection.

  The Siphoner leader considered the offer for a long moment. Around them, the Capillaries watched in silence, their hollow eyes tracking the exchange with something like curiosity.

  "Three patients," Sero said finally. "We have three Siphoners whose wounds have resisted conventional treatment. If you can save all three, I will grant your passage."

  "And if I save two? Or one?"

  "Then you will have demonstrated skill, but not sufficient value. The price remains the same." Sero's thin smile returned. "All or nothing, Doctor. Do we have an agreement?"

  Elias didn't hesitate. "We have an agreement."

  Sero gestured, and Capillaries moved forward to cut their bonds. Elias rubbed his wrists, restoring circulation, as he was led toward the far wall where the wounded Siphoners lay.

  There were three of them, as Sero had said. All in bad shape.

  The first was a young woman, perhaps twenty-five, with a deep abdominal wound that had been crudely stitched closed. Infection had set in—Elias could see it in the inflammation around the sutures, smell it in the sour odor that rose from her body. She was feverish, delirious, her body fighting a losing battle against sepsis.

  The second was an older man, his leg crushed from mid-thigh down. The damage was catastrophic—bone fragments visible through torn tissue, blood vessels compressed or severed. The Capillaries had applied a tourniquet to prevent him from bleeding out, but without proper treatment, he'd lose the leg at minimum. More likely, he'd die from shock or secondary infection.

  The third was the worst. A young man, barely more than a boy, with burns covering sixty percent of his body. His breathing was shallow, labored, his airways compromised by smoke inhalation. The burns were full-thickness in places, down to muscle and bone. By any reasonable standard, he should already be dead.

  "These aren't wounds," Elias said quietly. "These are death sentences."

  "Which is why conventional treatment has failed," Sero replied, standing nearby with his arms folded. "Your predecessors have all tried. None have succeeded."

  Elias studied the three patients, his medical training cataloging the damage, calculating survival probabilities, planning treatment protocols. Under normal circumstances, in a proper hospital with full resources, he might save one of them. Maybe two, with luck and aggressive intervention.

  But this wasn't a hospital. He had no antibiotics, no surgical equipment beyond basic tools, no blood for transfusions—

  No. That wasn't true. He had blood. His own reserves, accumulated through harvesting, available through the Tower's interface.

  Blood Reserves: 6.1 L

  He could use his harvested blood for transfusions. The Tower's system was designed for it. But that would cost him—potentially cost him the ability to stabilize Lira, to keep her Soul Integrity above the critical threshold.

  It was a risk. But the alternative was certain death.

  "I need my medical kit," Elias said. "And access to clean water. And—" He paused, considering. "Is there a Transfusion Altar in this outpost?"

  Sero raised an eyebrow. "There is."

  "I'll need to use it. For blood transfusions."

  "That blood would come from your own reserves."

  "I know."

  The Siphoner leader studied him for a long moment, then nodded. "Bring his kit. And clear a path to the Altar."

  Elias got to work.

  The woman with the abdominal wound came first—she was closest to death, sepsis spreading through her system. He cleaned the wound, removing the crude stitches and draining the infection. His hands moved with practiced efficiency, decades of emergency medicine compressed into movements that were almost automatic.

  He used the Altar to transfuse her—one liter of his harvested blood, converting it through the Tower's system into something compatible with her biology. The process was strange, watching his reserves decrease as the woman's color improved, as her fever began to break.

  Blood Reserves: 5.1 L

  The man with the crushed leg came next. This was more complex—surgical intervention required, damaged tissue removed, blood vessels reconnected where possible. Elias used Cardiac Overclock to steady his hands during the most delicate work, the Circuit's enhanced precision allowing him to perform microsurgery with improvised tools.

  Vitality: 45/100

  Another transfusion, half a liter this time, enough to replace what the man had lost without depleting Elias's reserves completely.

  Blood Reserves: 4.6 L

  The burn victim was the greatest challenge. Elias worked for what felt like hours, debriding dead tissue, stabilizing airways, applying what primitive bandages he could fashion from available materials. The young man's survival was still uncertain—burns this severe required weeks of intensive care, skin grafts, constant monitoring.

  But when Elias finally stepped back, the patient was breathing easier. His vital signs had stabilized. Against all odds, he was still alive.

  Blood Reserves: 3.1 L

  Vitality: 55/100

  Elias stood over his patients, exhausted, his hands trembling from the strain. All three were stable. All three would survive—at least long enough to receive continued care.

  He turned to Brother Sero, who had watched the entire procedure in silence.

  "Done," Elias said. "They'll live."

  Sero approached the patients, examining each one with those pale, unreadable eyes. He touched the woman's forehead, felt the man's pulse, studied the burn victim's improved breathing.

  When he straightened, there was something new in his expression. Not warmth—Elias doubted the man was capable of warmth—but respect.

  "You've done what our healers could not," Sero said quietly. "You've saved three of my people—not through blood magic or Tower sorcery, but through skill. Through training. Through the simple application of knowledge most Climbers have forgotten exists."

  He turned to face Elias directly.

  "A deal is a deal, Doctor Thorne. You and your companions may pass through the Vineyard's territory unharmed. My Capillaries will escort you to the boundary of Floor 16."

  Relief flooded through Elias, so intense it nearly buckled his knees. They were going to live. Against all odds, they'd negotiated their way through an impossible situation without losing anyone.

  "Before you go," Sero added, his voice taking on a different tone. "A gift. In recognition of your service."

  He gestured toward the Altar—a proper Transfusion Altar, larger and more elaborate than the ones Elias had seen on lower floors.

  "You've earned access. Use it as you will."

  Elias approached the Altar, the familiar interface appearing in his vision as he drew near.

  TRANSFUSION ALTAR, READY

  AVAILABLE BLOOD: 3.1 L

  AVAILABLE CIRCUITS: COAGULATION SHIELD (INTERMEDIATE)

  INSTALLATION COST: 2.5 L

  INSTALL NOW?

  Coagulation Shield. A defensive Circuit—the description promised the ability to rapidly clot blood at wound sites, creating temporary barriers against damage. It would make him harder to kill, harder to bleed out in combat.

  He confirmed the installation.

  The sensation was different this time, a warmth spreading through his blood vessels, a thickening feeling as if his blood itself was becoming more responsive, more controllable. When it ended, he felt changed. Stronger. More resilient.

  CIRCUIT INSTALLED: COAGULATION SHIELD

  EFFECT: Rapidly clot blood to seal wounds. Creates temporary damage absorption. Duration: 5 seconds. Cost: 8 Vitality per use.

  Blood Reserves: 0.6 L

  Circuits: 3 (Blood-Sight, Cardiac Overclock, Coagulation Shield)

  Brother Sero watched the installation with obvious interest. "Three Circuits now. You're becoming quite formidable, Doctor."

  "I'm becoming what I need to be."

  "Yes." The Siphoner leader's expression grew distant. "That's what the Tower does. It shapes us into what it needs us to be. Whether we want it or not."

  He walked Elias back to where Mira and Lira waited, the Capillaries parting respectfully before him.

  "You're free to go," Sero announced. "My people will guide you to the edge of our territory. Beyond that, you're on your own."

  Elias nodded, gathering his supplies, checking that Mira was ready to move. But before they could depart, Sero's hand caught his arm—a grip that was surprisingly strong for such a gaunt frame.

  "One more thing, Doctor."

  Elias turned.

  Sero's pale eyes met his, and for a moment, there was something almost human in them—a warning, perhaps, or a prophecy.

  "You've saved lives today. You've used your blood to heal rather than harm. That's admirable. Rare, in this place." He paused. "But the Tower always collects its debt. Every gift it gives, every power it grants, has a price. And the price is always paid in blood."

  His grip tightened.

  "You carry your daughter's soul within your own vitality. You've bound yourself to her in ways the Tower recognizes and... exploits. The higher you climb, the more the Tower will demand. And eventually, you'll face a choice that can't be negotiated away."

  "What choice?"

  Sero released him, stepping back, his expression smoothing into its usual calm emptiness.

  "The Tower always collects its debt, Doctor Thorne. Remember that, when the time comes."

  He turned away, ascending the platform once more, his attention returning to the blood vats that pulsed at the center of his cathedral.

  Elias watched him go, Sero's words echoing in his mind. Then he gathered Mira and Lira, and they followed their Capillary escort toward the exit, leaving the Vineyard's heart behind.

  Soul Integrity: 95.7%

  The number had improved slightly, a result of the rest, perhaps, or some effect of the Altar's use. But the warning remained.

  The Tower always collects its debt.

  And Elias's debt was growing larger with every floor.