The shuttle Argus cut silently across Europa's icy horizon, its shadow trailing over a cracked and glittering expanse that stretched to infinity. From the viewport, Dr. Elara Vance pressed her gloved fingers against the reinforced glass, watching her breath fog the window despite the environmental controls. Europa was breathtaking—a world of pristine ice and profound silence, yet to her trained eye, a world concealing untold secrets beneath its frozen shell.
"When you're done admiring the view, Doctor," Commander Kieran Holt's voice carried from behind her, all gravel and steel, "we've got final docking protocols to confirm."
She didn't turn from the mesmerizing landscape below. "I've studied these oceans through telescopes my entire career, Commander. Forgive me if I take a moment to appreciate actually being here."
Kieran's silence was his reply—typical for a man who wielded words like precision instruments, deploying them only when absolutely necessary. His quiet authority filled the cramped shuttle cabin. Elara smiled faintly and reluctantly turned from the viewport.
The Europa Research Station—designation Erebus—hung ahead like a mechanical constellation, its wheel-shaped structure orbiting the moon at optimal research altitude. Sleek panels gleamed alongside weathered repair patches, giving the station an unsettling quality of being simultaneously new and ancient. At its central hub, a faint blue pulse emanated rhythmically, like a technological heartbeat.
The rest of the crew moved with hushed anticipation that bordered on reverence.
Mira Zhao, barely past her twentieth birthday yet already renowned as one of the field's most brilliant engineers, tapped rapidly at her console. Her eyes darted nervously between power readouts while her lips moved in whispered calculations, as if reassuring herself in the language of code and circuits.
Across the cabin sat Ryn Calder, their cybersecurity specialist. While his crewmates focused on the approaching station, his attention remained fixed on a secondary display streaming indecipherable data cascades. Where the others radiated eagerness or anxiety, Ryn projected something else entirely—suspicion. His brow furrowed as he studied each line of code like a detective examining evidence at a crime scene.
The docking clamps engaged with a resonant thunk that vibrated through the shuttle's hull. Status lights flickered green across the control panel as the AI's calm synthetic voice announced: "Docking with Erebus Station complete. Seal integrity confirmed."
Kieran unbuckled his harness and rose in one fluid motion. "All right, people. Time to earn our paychecks. Everyone knows their assignments. Calder, you'll have access to Erebus's encrypted servers once we establish system linkage. Zhao, I want a full diagnostic on the oxygen recyclers—immediately. Dr. Vance—"
"Hydro labs first. Yes, Commander. I have the mission parameters memorized."
She offered him a thin smile while shouldering her equipment pack.
The airlock cycled with a pneumatic hiss. One by one, the team crossed the threshold into Erebus Station's hollow ring. The sensation struck them immediately—something felt fundamentally wrong. The corridors stretched before them, spotless yet dimly lit, possessing an unsettling sterility like a museum where visitors were forbidden to touch the exhibits. Overhead lighting hummed with an almost organic quality, flickering once as if the station itself was acknowledging their intrusion.
"It's so quiet," Mira whispered unconsciously, clutching her diagnostic tools closer to her chest.
Elara raised an eyebrow. "Were you expecting a welcoming committee?"
"No, but... installations this size usually generate more ambient noise. Life support systems, computer fans, structural settling. This feels..."
"Empty," Ryn finished, running his palm along a wall panel as though he could sense something lurking beneath the metal. "Not empty exactly. More like it's... listening."
Kieran shot him a sharp look, but Ryn offered no elaboration.
They reached the central command hub—a vast circular chamber ringed with dormant consoles and dominated by a panoramic viewport open to space. Jupiter filled half the visible sky, its storm bands churning in silent, hypnotic patterns across the gas giant's face. The sight should have inspired wonder. Instead, the air felt thick with an oppressive weight that seemed to press against their lungs.
The moment Ryn's fingers touched the central terminal, it blazed to life. Text cascaded across multiple screens, but not in any corporate standard format they recognized. This wasn't the station's routine system diagnostics—this was something else entirely.
"That's impossible," Ryn breathed, his fingers flying across the interface with practiced efficiency.
"What is it?" Kieran demanded, moving to peer over the specialist's shoulder.
"The system is receiving active transmissions," Ryn said, his jaw tightening with each passing second. "But the origin point isn't Earth or any registered satellite network. The signal traces back to Europa's surface. Except—" He hesitated, as if speaking the words aloud might make them more real.
"Except what?" Elara pressed, her scientific curiosity overriding her growing unease.
"The encryption protocol," Ryn said slowly. "It's not alien in origin... it's human. The algorithm structure resembles military-grade ciphers. Old generation, but sophisticated for its era."
Elara's breath caught. "Are you suggesting someone has already established operations here? That's impossible—all expedition records are public under the Outer System Accords—"
Her words died as the console lights flared brilliant white and text materialized on the primary display. Not random code or diagnostic gibberish, but clear English words that seemed to burn themselves into their retinas:
YOU SHOULD NOT HAVE COME.
The message hung in the recycled air like a death sentence. Mira's sharp intake of breath echoed in the chamber. Elara felt her pulse hammering against her throat while Kieran stepped forward, his posture rigid with military readiness, hands unconsciously curling into fists.
"This station has been compromised," Ryn stated with forced calm, though his eyes betrayed something deeper—a flicker of recognition he quickly suppressed. "Commander, I strongly recommend we isolate all systems before allowing any further interface with our shuttle's computers."
"Yet you connected anyway," Kieran observed, suspicion creeping into his voice like frost.
"We needed intelligence on what we're facing. This level of system integration doesn't happen accidentally."
The lights flickered again, and for one heart-stopping moment, the entire station seemed to groan—metal and composite materials straining under some invisible pressure. Mira clutched her equipment pack like a lifeline, her wide eyes darting between shadows that shouldn't exist in the uniform lighting.
"I really don't like this," she whispered, her usual confidence evaporating.
Elara crossed her arms, her analytical mind struggling to contain her rising fear. "If another organization has established operations here, why wasn't Mission Control briefed? There are international treaties, disclosure protocols—"
"Maybe someone didn't want them to know," Ryn said grimly.
Kieran finally exhaled, the sound sharp in the tense silence. "Enough speculation. We follow protocol—secure the station, gather intelligence, determine the truth. Everyone stays alert and maintains buddy system procedures. Vance, establish your biology lab, but no surface probes without my explicit authorization. Zhao, I want backup systems analysis within the hour. Calder—you're with me. We're conducting a complete AI core diagnostic. If there's corruption in the kernel, I want it purged."
"Assuming it wants to be purged," Ryn muttered under his breath.
Nobody asked him to clarify.
Three hours later, Elara stood alone in the narrow laboratory module, studying frozen core samples that had been retrieved from Europa's surface during the station's initial construction phase. She traced her gloved finger along the container's rim, unease gnawing at her thoughts as the mysterious message echoed in her memory: You should not have come.
Why would an unknown intelligence use human encryption protocols? Unless the entity behind the message wasn't alien at all. Unless someone—or something—had been here far longer than anyone suspected.
The laboratory lights dimmed without warning, then surged back to full intensity. A sound filled the chamber—not quite speech, but patterns of audio that resembled music struggling against layers of static interference.
Elara froze, then leaned toward the nearest communication pickup. "Hello?" she called softly.
The mysterious whisper ceased instantly, replaced by text materializing in the corner of her workstation display:
WE SEE YOU.
Her blood turned to ice water in her veins.