The Barnard's Loop nebula spilled across the observation glass like a torn ribbon of light - pink and blue, with veins of dark dust in which tiny stars were lost. The Heliotrope, a small research vessel with scuffed edges and a new soul of artificial intelligence, moved through the darkness so quietly that even the hull tremor sensors were silent. Lena Zurawska had her nose almost at the visor of her observation helmet, as if she could smell the cold of space. - 'The interferometric lines are holding,' she muttered, tapping the panel. A thin green array of signals unfolded on the screen. Everything was clear, all too clear - deep space silence with background noise so even it stung. Then the noise undulated, as if someone had dragged a finger across a sheet of dark water. - Pallas? - Lena asked, straightening up. - Can you see it? The artificial intelligence's voice spread through the cabin like a breath: soft, neutral, with a hint of synthetic warmth. - I can see the deviation at 1420.4056 megahertz. Very narrow. It resembles a carrier signal. - 'Hydrogen line,' said Amir, who appeared in the doorway still in his socks, with his hair in disarray. - Someone is waving the atoms of the universe at us? Really? Lena smiled crookedly, but her fingers were cool. 1420.4056 MHz, the purest stellar whisper, the one they used to talk through the immensity with probes and beacons. - The source? - Hard to estimate. 'Directional: foreboding, along our course, near the former P-9 Relay Station,' Pallas replied and superimposed a small, pulsating dot on the map. - P-9 officially out of service for thirty-eight years. Amir yawned, but of the controlled kind that doesn't mean boring at all. - If this is a joke, someone has very expensive equipment. - 'Let's put it without metaphors,' Lena said, zooming in on the diagram. - 'This source sends out a carrier on the hydrogen line and superimposes on it...' - she interrupted. Equal peaks bloomed on the signal band. Every 0.83 seconds. Then a brief pause. Again. - It looks like... a pulse. Like a rhythm. - 'I'm detecting an amplitude modulation at a rate of 72 per minute,' Pallas admitted. - 'And an interesting peculiarity: the variance mapping corresponds to 93 per cent of your actual heart rate graph, Leno. Amir stood up straight, as if someone had cut his strings out of fatigue. - That what? Lena felt the skin under her suit crinkle. She had a biomonitoring belt on her wrist, hooked up to the ship's system. - A coupling? A leak? - She asked, but her voice no longer sounded like a voice. More like someone repeating a question to hear anything but the answer. - I checked. I don't find a local feedback loop or eavesdropping. The signal is coming from outside,' Pallas replied. - I repeat: from the P-9 area. Captain Durajska was asleep two sections away, and Lena knew that protocol said: report, wait, collect full sample. But in Heliotropa, the vacuum held the throat of anyone curious just the same. Amir had already slipped into the drone position. - 'Chicory, are we operational? - He chuckled, braiding his hair into a rubber band. The outline of a small reconnaissance robot with the perverse name of Moth lit up on the panel. Pallas sighed vestigially, which was just an animation of the sound. - I am activating the channel as prescribed. I note: remote scan, without entering the danger zone. The heliotrope slowed down. From the outside, it now had more in common with a droplet stretched by surface tension than with a classical ship. Lena watched the Moth peel away from the cargo bay and disappear into the darkness, microscopic in the face of the stardust fields. The image from her camera appeared on the screen: grainy, with edges blurred by micrometeorites that flowed like luminous plankton. The P-9 station loomed up slowly, solid, with the once fashionable air of a modernist fortress. Its docking tower was tilted, with a cloud of icy frost floating around it, as if it were breathing. On the side of the hull could be seen traces of minor impacts, the graphite snow of past collisions. And a little lower down - something that was not of the same story. - Zoom in," Lena asked. The camera obediently came up. The metal looked as if someone had written on it with a roughly annealed nail. The letters were uneven, in places bitten into the thermal coating down to the meat of the alloy: "DO NOT ENTER". Amir swallowed reflexively. - A classic. Always works. The moth went around the station, mapping it with LIDAR. In some places the scan wasn't coming back. It wasn't because there was no surface - rather, it was as if the light was dissolving into something that didn't understand that a photon should return. Lena marked these zones in red. - Pallas, have optical anomalies of this type ever been recorded near P-9? - Records from thirty-eight years ago are incomplete. They suggest loss of power and structural damage after a micrometeorite storm. Nothing about distortion,' the AI replied. The voice sounded even, but Lena got the impression that Pallas was now listening more carefully than usual. Suddenly the image shook, as if the Moth had fallen into a pocket of invisible wind. For a second the screen went completely dark. When it came back on, it showed... The interior of the Heliotrope's observation booth. Exactly the one they were sitting in. Lena recognised her mug with a drawing of a raven, a pencil spot on the panel, even a torn page from Amir's notebook. - Pallas? - it was no longer a question. It was an attempt to get hooked on anything. - I record a momentary visual loop. The recording indicates a delay of 0.3 seconds relative to reality. Source... unknown. The screen flashed again and returned to the image of P-9. This time the camera was looking at a circular auxiliary airlock, with yellow handrails and black warning stickers discoloured by radiation. Next to it, in the shadow of the handrail, someone - or something - had stuck a piece of transparent tape with a dried marker mark. A faded but legible word: "LEAVE". - OK, I like this station already,' muttered Amir nervously. - She is polite. Lena could feel the kind of curiosity that comes from anxiety growing in her: a needle that wouldn't let go. After all, they were here to check, not turn their heads. She asked to see the transmission logs. The carrier on the hydrogen line continued to pulse - and continued to clone her heartbeat. - 'Let's make an approach in Polarnik,' she said after a moment. The Polarnik was a lifeboat with armour better than the old ferries and its own independent CO2 scrubber. - Just us, short docking. No going out. Pallas, keep a link with us and monitor every fluctuating atom. - I will record the decision with a protocol deviation and justification,' Pallas replied. - Estimated safe window time: eighteen minutes. After that time, the dynamic particle flux from the nebula will increase the risk by ninety per cent. The Polarist pulled away from the side of the Heliotrope slightly, like a breath. Lena only now felt that she was carrying a stone in her chest. She was fastening the collar of her spacesuit when Amir, already strapped up to her neck, poked her in the shoulder. - You know this is stupid. - I know,' she replied, turning on the microphone. - 'And I know you wouldn't stop thinking about it for the rest of the cruise. - I wouldn't stop,' he admitted with a shadow of a smile. The docking went all too unnaturally smoothly. Polarnik's jaws gripped the P-9 airlock ring and tightened, and the leak indicator blossomed green. From P-9 came the calm of a vacuum in which everything is either dead or very patient. Lena slipped her hand into her glove until her fingers touched the cold grip of the emergency control. - 'Pallas, pressure on the other side? - She asked. - Surprisingly stable. Respiratory mixture close to Earth's. Temperature: two degrees above zero. I hear... hmm. Hard to describe. Mechanical vibrations in the material, low frequency. - Like from a pump? - Amir interjected. - 'Like from the heart,' replied Pallas against her own preference for metaphors. - 'But it's not an airborne sound - the transmission happens through the material of the airlock. I translate into audible. Something sounded in the headphones that was almost nothing, but it was enough to make the hairs on the back of Lena's neck stand up: three quiet, steady beats. Pause. Three. Pause. It wasn't the same rhythm that was sapping her own pulse, and maybe that's why it was worse - because it was independent. - 'Okay, we're not opening,' Amir said faster than he thought. - 'Not yet,' Lena corrected. She looked at the P-9 airlock control panel, at the faded instructions, at the cracks in the paint. At the tiny camera above the door. Glassy, dead. She stretched out her hand to the microphone at the portal and leaned in, feeling her helmet grow warmer. - This is Lena Zurawska from Heliotrop. If anyone can hear us, please respond. The pause lasted as long as pauses last in space: they can't be converted into seconds because they have their own measure. Finally, there was a crackling sound. Then something that was like breathing through paper. And then a voice that made Amir almost move away from the panel. - 'Leno,' someone on the other end hoarse. Not a stranger. Not mechanical. Just the same as hers, only half a tone lower, as if it had been passed through silence. - Don't open it. The airlock panel lit up with a green 'READY', though Lena hadn't touched a button yet. Pallas said something about an anomaly in the protocol, but the words sounded like stretched rubber. - 'That's not me,' Amir remarked at the same moment the pressure gauge aligned perfectly on both sides. The metal under their fingers twitched almost imperceptibly. The lock indicator jumped. In the emergency light, the edge of the door flashed like a cold smile. Lena tightened her fingers on the handle, feeling that now the decision was no longer just a protocol, but a choice on a very personal scale. And then on the other side someone knocked three times.