The Last Signal from Europa

Dr. Sarah Chen stared at the spectrograph, her coffee forgotten and growing cold in zero gravity. The signal shouldn't exist. Europa Station had been monitoring Jupiter's fourth moon for three years without incident, but seventeen hours ago, everything changed. 'Play it again,' she told the AI. The audio filled the observation deck - a rhythmic pattern of pulses that rose and fell like breathing. Not random. Not natural. Commander Torres floated into the room, his expression grim. 'Tell me you've found a glitch,' he said. Sarah shook her head. 'It's coming from twelve kilometers beneath the ice. The subglacial ocean.' 'That's impossible. Europa's ocean is sterile. We've confirmed it a hundred times.' 'Then something down there wants us to know otherwise.' The crew gathered for an emergency meeting. Five scientists, one engineer, one commander - all of them 628 million kilometers from Earth, orbiting a moon that wasn't supposed to be calling out to them. 'We drop a probe,' suggested Dr. Yuki Tanaka, the team's astrobiologist. Her hands trembled with excitement. 'This could be first contact.' 'Or it could be a trap,' countered Torres. 'We don't know what's generating that signal.' But curiosity won, as it always did with scientists. They designed the probe to be simple - a reinforced sphere with cameras, sensors, and a powerful transmitter. It would melt through the ice and dive into the ocean below. The descent took six hours. At first, the cameras showed nothing but darkness and ice. Then, at ten kilometers depth, something changed. Bioluminescence - faint at first, then stronger - began to pulse in rhythm with the signal. 'My God,' Yuki whispered. 'It's alive. All of it.' The entire ocean was glowing, undulating with coordinated light patterns that spread for kilometers. The probe's sensors went haywire, detecting complex chemical signatures, electromagnetic fields, massive thermal vents. This wasn't just life - this was a biosphere, thriving in the dark. But then the signal changed. The pulsing became frantic, erratic. The probe's cameras caught movement - massive shapes gliding through the water, each one the size of a city block. They weren't swimming toward the probe. They were fleeing from something deeper. 'Pull it back,' Torres ordered. 'Now.' 'Wait,' Sarah said, her eyes locked on the screen. 'Look at the depth reading.' The probe was being pulled down. Not by gravity, but by something else. The cameras showed it now - rising from the absolute depths of the ocean, a structure so vast the probe's lights couldn't illuminate its edges. Geometric. Deliberate. Ancient. And it was activating. Light erupted from the structure, blinding the cameras. The signal transformed into something that made their equipment scream warnings. Then, clearly and terribly, they heard it - not through the probe's audio, but broadcast directly to their minds: 'CONTAINMENT COMPROMISED. ANALYSIS: HUMAN. DECISION: STERILIZATION PROTOCOL INITIATED.' Sarah's last transmission to Earth was simple: 'Do not come to Europa. Do not send help. Quarantine the Jovian system.' The signal went dead. Back on Earth, mission control watched helplessly as Europa Station's beacon vanished. When they turned their telescopes toward the moon, they saw it was no longer white. It was glowing.