Lieutenant Junior Grade T’Luni’s eyes opened first the next morning, her acute Vulcan senses noting a distinct shift of colour across the stone ceiling above. The silvery twilight that had lingered while they slept was replaced once again by the warm, golden hue of the afternoon daylight.

Across the chamber, Tanna Irovin stirred from inside her sleeping bag. “Morning already?” she mumbled, emerging slowly from her warm cocoon, rubbing the sleep from her eyes. “It feels like we just went to sleep.”

“Morning appears to be… relative,” T’Luni replied, glancing towards the ceiling. “The light has shifted to diurnal patterning – synchronised with our circadian rhythms.”

Craig tossed his sleeping bag off his face and fumbled for his glasses. “You’re saying it’s matching us?”

“It would appear so, Commander,” T’Luni answered.

“Maybe the planet is just being hospitable?” Tanna said, giving a small, uneasy laugh.

Craig grunted, pulling on his boots. “Hospitable or not, we’ve got exploring to do. Let’s hit a quick breakfast, then see where that corridor leads.”

As they ate, the trio discussed a plan for how to proceed. It was decided they would go as far as they could in six hours, then, if no notable discoveries were made, they would head back to base camp and try a second door tomorrow, repeating the process until they explored all seven of the doors. If nothing remarkable appeared after one week, the team would pack up and head back to the Leif Erikson.

Just before they left, Craig tapped his commbadge. “Away Team to Lief Erikson. We are about to journey deeper into the complex. We will check in again in two hours.”

“Copy that, Commander,” replied Captain Bowman’s voice after a moment, “Keep us posted.”

Craig slung his pack over his shoulder, then, together, the team moved towards the large, open doors. The corridor beyond again sloped gently downwards, taking them further below the planet’s surface, and it was punctuated by the same unnatural light shafts. One by one, they crossed the threshold into the hallway, and as soon as the last of them passed the doorway, the great doors rumbled closed behind them. The sound rolled down the corridor like distant thunder.

They pressed deeper and deeper into the tunnels, their tricorders humming softly as they went. The stone walls were smooth and seamless, without a single discernible tool mark. Every so often, they came across another relief carved into the wall, the same beautiful, alien artistry, showing the same elongated humanoids kneeling or praying to a deity without a face, save for swirling eye holes.

Cruikshank knelt beside one of these reliefs, scanning it. “These carvings are thousands of years old, if not more.”

“And yet,” T’Luni added, lowering her tricorder, “There is no sign of erosion at all. The air here is incredibly stable. Precisely sixteen point two degrees Celsius. The humidity has also been consistent throughout. It seems plausible to suggest that the tunnels have some way of monitoring and adjusting their environment.”

“You think it’s automated?” Irovin asked.

“Presumably,” T’Luni answered, nodding her head, “But I find the lack of technological evidence… disturbing.”

“Yeah, no visible wiring. That’s what’s disturbing about this place,” Irovin said with a smirk.

The team continued on, the passage twisting and descending at the same gentle slope. The lights overhead continued to spark into life as they went, going dark again after they had gone. After nearly two hours of exploration, they came to a small square chamber with doorways set into three of the four walls. They decided to stop and take a break, snacking on protein bars and water as they sat on the cold stone floor.

“Hold up…” Cruikshank said, gulping down a large bite of the brown ration bar. “What’s that?”

He stood, sweeping his light over the floor at the far side of the chamber. The fine powder of dust that coated the stone floor had been disturbed, scattered in arcs and uneven streaks.

Footprints.

They weren’t fresh, but they had been made recently enough that the dust had not settled back into place yet. They led from the tunnel opposite the one they had entered from, towards the tunnel on their right.

Lieutenant Junior Grade Irovin moved cautiously closer, her words barely a whisper. “Those… are not ours.”

“No.” Cruikshank replied, “But they are bipedal.”

T’Luni ran a quick scan of them. “The physiology suggests humanoid. Body mass consistent with your average Federation species. I detect traces of organic residue.”

“What kind of residue?”

T’Luni’s brow furrowed. “I am unsure. It is carbon-based, perhaps skin cells?”

“So not only is there something else down here, it’s barefoot?” Irovin asked, her voice pitching up slightly with panic.

“That is a possibility,” T’Luni answered with a nod.

Irovin’s head darted from doorway to doorway. “What if it’s watching us right now?”

Cruikshank put a hand gently on her shoulder. She flinched. “Let’s not jump to conclusions,” he said. His voice sounded calm, but there was a tension behind it. “We’ll follow the trail for a short distance, log that data, then contact the ship.”

They advanced cautiously, the sound of their boots echoing softly off the ancient walls. The tracks wound through a narrow corridor for a ways, then opened into a circular chamber. The walls of this chamber were also covered with carvings, but these were much cruder, more hurried than the ones from above. More figures bent in supplication before the deity. The lines seemed to twist when viewed from the periphery, as if they somehow resisted focus.

“I don’t like this…” Irovin said, her voice shaking a little.

T’Luni’s voice was still calm, but it was quieter than usual. “I concur.”

Before Cruikshank could say anything to reassure his team, his tricorder chirped. There was a faint life sign reading ahead, but it was barely detectable. He looked up toward the darkened corridor beyond.

“Contact,” he said, his voice all but a whisper. He pulled his glasses off his face, then, using the back of his sleeve, wiped the sweat from his brow before replacing them.

A low sound drifted from the tunnel, half whisper, half movement. It was the kind of sound that could just as easily have been or not been footsteps.

Irovin felt her pulse quicken. She could hear it pounding in her ears as she strained to listen for any sounds issuing from the hall ahead of them. “Did you hear that?’

Cruikshank nodded, then slapped the commbadge on his chest. “Away team to Lief Erikson. We’ve found evidence of habitation. We are proceeding with caution.”

There was a hiss of static, then Commander Saberwyn’s voice broke through. “Copy that, Commander. We are registering minor interference, but we’ve got our ears on. I have a lock on your biosigns, so we can pull you out if it gets too real down there. Stay safe, Lief Erikson out.”

Without warning, the next light shaft in the tunnel blazed open, sending its bright daylight cutting down through the dark, illuminating the dust like flakes of falling snow.

Then, something on the far edge of the light moved.

It stepped slowly forward into the column of light, and all three members of the away team froze, speechless, in awe of this creature that was both very much alive and unlike anything they had seen before.

It stood taller than any of them, perhaps six and a half feet, with long limbs that were graceful and sinewy. Its skin was coloured like pale stone, almost alabaster, traced faintly with veins of luminescence that pulsed below the surface like slow-motion bolts of lightning. In the half-shadow, those patterns shifted gently, fading and brightening in rhythm with its breathing.

Its face was angular and narrow, with features carved in near symmetrical precision. The eyes, larger than a human’s and pale silver, had pupils that were elongated slightly along the vertical axis, which caught the light from above and reflected it like two shards of moonlight. When it blinked, the movement was slow and deliberate, almost assessing.

A soft sound filled the chamber. Not speech exactly – something more musical and harmonic, as though several tones resonated at once in its throat.

T’Luni’s tricorder trembled slightly in her hands as she scanned the being. “Humanoid structure. Carbon-based lifeform. Oxygen breathing. But…” she tilted her head slightly, “…there are anomalous bioluminescent tissues, especially along the temples and spine.”

“Friendly posture?” Cruikshank asked, keeping his voice low.

T’Luni nodded. “It appears non-aggressive, perhaps even curious.”

The being stepped closer, light playing across the soft, flowing fabric that draped its body. The garment was simple, woven from fibres that seemed to shimmer when they caught the light, but across its chest hung small, carved ornaments and smooth stones that seemed to glow from within. Some bore the same symbols that were carved into the walls.

Irovin swallowed hard, and the being turned its gaze on her. The air in the chamber seemed to tighten for an instant, and she took a reflexive step backwards. Then, with a single fluid motion, it raised one slender hand of slightly webbed fingers and pressed its palm gently against its chest, in what looked like a gesture of greeting.

Irovin, unable to help herself, let out a deep sigh of relief. Cruikshank cleared his throat, then mimicked the gesture. “We come in peace,” he said, his words echoing faintly off the stone walls, “We mean you no harm.”

The being tilted its head. The luminous lines on its temples brightened briefly, and then – quite unexpectedly – it spoke.

The sound was melodic, with harmonic undertones weaving through the words like a second voice whispering just below the first. The universal translator struggled for a moment, garbling the first few syllables before catching the pattern.

“…surface-walkers,” the translation finally rendered, soft but clear. “You have walked beneath the forgotten sun.”

Cruikshank blinked, looking towards T’Luni. “Did it just…”

“Yes,” she replied. “The translation matrix is adapting. Their syntax is… poetic.”

The being waited, head tilted slightly, the light tracing patterns on its temples. Finally, Cruikshank took a step forward, lowering his tricorder. “I am Lieutenant Commander Craig Cruikshank. These are Lieutenants Junior Grade Tanna Irovin and T’Luni. We are scientists of the USS Leif Erikson.” He gestured to each of them as he spoke their names aloud.

The being followed his hand, its gaze lingering on each of them in turn, with an unreadable expression on its face. When it replied, the harmonic undertones vibrated the air subtly, almost to be felt more than heard.

“I am called Seru’nai,” they said slowly. “Voice of the Cavern, and Keeper of the Gates.”

T’Luni inclined her head slightly. “An honour, Seru’nai.”

Seru’nai’s eyes flicked to her. “T’Luni.” They repeated her name with startling precision, the layered tones of its voice turning it into something musical. “You carry a calm, like the upper-winds.”

T’Luni arched an eyebrow. Irovin looked mildly uncomfortable. “They can tell that?”

Seru’nai turned to her next. “And you, flame in motion. The light bends to you.”

Irovin blinked, whispering under her breath, “Okay, like that’s not creepy at all.”

Cruikshank hid a small smile, then gestured towards the walls. “Your people… they built this place?”

Seru’nai’s expression shifted slightly. An almost imperceptible tightening of the features. “Not built,” they said softly. “Found. The Stone was before us. We walk where the Old Voices walked.”

Seru’nai motioned to the tunnel beyond, beckoning with a grace that seemed to be at once both an invitation and a command. “You will come. The Elders will wish to see the Surface-Walkers.”

Cruikshank tapped his commbadge. “Cruikshank to Erikson. We’ve made contact with a native inhabitant. They’re taking us deeper into the complex.”

Static crackled. A faint voice came through, distorted slightly. “ – repeat – signal weak – keep – open channel –”

The rest was a wash of static and interference.

Cruishank frowned, then sighed. “Figures.”

Lieutenant Irovin glanced back towards the tunnel they had come from. “We’re not gonna have comms down there, are we?”

“Not reliable ones, by the sound of it,” Cruikshank replied. “C’mon, let’s get moving.”