The research station 'Helios' drifted quietly on the edge of the Whispering Nebula, illuminated by the blue-violet light of distant stars. Captain Lena Krawiec watched through the porthole as the nebula's softly diffused light reflected in her eyes. Her crew - Dr Elijah Heller, a specialist astrobiologist, and space engineer Iga Sowicka - were just completing the final preparations for the mission to go out. The nebula had always been a subject of fascination: no radio signal had passed through its heart, and probes sent into its depths had disappeared without a trace. The Helios team was about to explore it up close for the first time. As Lena closed the hatch to the airlock, the tension was palpable in every word. - Communication systems checked? - Iga asked, running her finger over the holographic screens. The electronics were failing, as if the nebula was even affecting the station's plating. Elijah adjusted the microphone on his helmet, trying to hide the tremor in his voice. - 'If anything goes wrong, we're going back immediately,' Lena decided. With a swish of adjusted air, they left the station and headed towards the pulsating cloud, where the light seemed to dance and ripple. Immersed in weightlessness, they descended deeper and deeper into the endless purple glow. With every metre they could feel the walls of the nebula getting closer and closer to them. At one point, a whisper, unidentifiable, sounded in Iga's helmet: - Can you hear it? - She asked, stopping abruptly. Her pulse was visible on Lena's screen, beating faster. Elijah looked at her in disbelief, but after a moment he heard the distorted voice himself, which seemed to come from inside their own thoughts. All the sensors went crazy. Light permeated the suits, pulsed rhythmically, and the nebula began to form something like a door in front of them - dark, still, inviting. The space around them vibrated, as if reality was no longer entirely stable. - 'Let's get closer,' Lena said, although her own voice seemed strangely alien to her. Suddenly, the panels of their suits began to flicker, their vital systems signalling malfunctions they couldn't fix. A shadow grew between them and the door.... something no human eyes had ever seen. Were they to return - or cross the threshold of the nebula? And who - or what - was the shadow that was approaching ever more slowly but inevitably?