Salt was collecting in white lines on the railing of the pier, and seagulls were drawing loud loops in the sky. After the night's storm, the sea was breathing heavily, pushing grasses torn from the bottom and bits of plastic onto the beach, which someone would try to collect again tomorrow. A fine mist drifted over the wave line - not the languid summer mist, but a rough one, returning sounds in thousands of droplets. Nina stood on a wooden platform by the signal box and tightened the head of the hydrophone, which hung from a steel cable, submerged in the water. On her wrist was a wristband - a small, graphite one with a thin screen. The armband was called the Drop and was her personal AI: it asked, warned, prompted, sometimes remained stubbornly silent. "Channel three calibration?" - blinked the Droplet in a blue dash. "Just one more minute." - whispered Nina, staring at the bars on the screen. The ripple graph, normally as calm as the breathing of a sleeping cat, looked like an earthquake reading. Post-storm disturbance is the norm, the mentor of the Young Coastal Network Operators programme always said. The norm ended, however, when the echoes returned before anyone sent a signal. "Nina!" - came running up from the other side of the platform, Tymon pushing a drone cart in front of him in the form of a silver 'Owl', with long, folding wings. "Can you see it too? Hydro channel running, and delays... negative." "I thought I'd hooked up the cable wrong," she replied, running her finger across the screen. "See." The drop opened a detailed preview. A ping sent from the port, in the alphabet of ultrasound: short, long, short. So far, so good. Except that the return graph - a thin, stretched line - had appeared on the timeline three milliseconds earlier. 'Negative three and two tenths,' read Tymon. "After all, that's... not how it works." "Give me the test signal," asked Nina. Tymon whistled high, briefly. The drop developed a spectrogram and hesitated, as if trying to time the sound. A thin streak of whistling appeared on the screen before the air around it moved Nina's hair. "It can't be a delay error in the rig". - Tymon was already unfastening the safety bolt on the Owl. "I'll check the optics. Maybe the LIDAR caught something." "We're not going up in this wind," she admonished him with a habit that had seeped into her over the last two years of volunteering. "Turn the detectors to the horizon." The owl did not fly. It merely spread its wings like a crane ready to take off and activated its array of sensors. A map shuddered on Tymon's tablet, with hundreds of LEDs shining on it - points of network nodes along the coast. One of them, branded as Dome 13, flashed red, then turned into a pulsating oval. "Dome 13?" - Nina furrowed her brow. "After all, it's in museum mode. Turned off." "And yet it's transmitting something." - Tymon zoomed in on the image. "And it has the same timing error." Dome 13 was the white, scratched shell of an old radar at the end of a cliff. As a kid, Nina used to look at it from afar, pretending it was a massive crayon stuck in the ground by a giant. Since the coastal network started using the old installations, the dome has become an educational object for tours, and later a decorative blowout. The wooden observation deck around it always creaked after the rain. "How far to the top?" - Nina asked. "Seven minutes upwind if you don't stop for photos," smiled Tymon crookedly. "I'm not going to!" - she replied, although her fingers wanted to pull out her phone themselves. The fog was pouring through the forest like an inverted waterfall, and waves were cutting through it, leaving nascent tunnels in the air. She felt like catching this shot. She grabbed Owl's belt and, together with Tymon, headed up the mountain. The path winded between pine trees and rosehip bushes. The smell of needles and salted air echoed the ozone she usually only smelled in the servery. Every now and then the drop vibrated with short, uncertain pulses. "I'm detecting a timestamp turnout within two hundred metres," she - she finally spoke. "The divergence increases with altitude." "By how much?" "Seventeen seconds and growing." Tymon blinked. "There's only supposed to be dead components in there. Or someone turned them on today." "And set the clock for next Thursday?" - Nina looked at him warningly. - "Focus. We're officially here to check out the anomaly." "Officially." - he confirmed. - "And unofficially?" "We'll be polite." Dome 13 rose from the mist suddenly, larger than Nina's memory. Its white surface was riddled with scratches and stains from salt storms; the metal fittings had tarnished to the colour of old coins. The museum doors - the ones for tours - were padlocked. Beside them, rusty as freckles, hung information boards about the history of radar and birds. But below, at the technical entrance, a green LED above the panel flashed. "Power?" - Tymon held out his hand. The panel accepted his volunteer card, though it shouldn't have. "That'll go in the logs." - muttered Nina, but did not withdraw it. The door hissed with a seal and gave way slightly. Inside, it smelled of dust, ozone and the sea. The hall was as round as the inside of a shell. In the middle stood something like a table - a control desk - and above it hung a delicate, transparent hair-like chandelier of fibre optics. Their ends glowed as if they remembered a recent flow of light. "There's no generator here," - remarked Tymon in a half-hearted voice. - "Where..." "From outside," Nina replied, hopping onto the step by the desktop. A thin layer of dust covered the screens, but beneath it smouldered signs. The drop hissed with a vibration that went over Nina's skin like ants. Letters appeared on the central screen, so dirty you could see the finger drawings of kids from years ago. NINA, READ SLOWLY. They didn't touch the keyboard. Tymon moved his hand away instinctively. "Who wrote this?" - his voice reverberated doubly from the dome, as if he couldn't decide which time to sound out. Before she had time to reply, the text shifted by a line. IF YOU CAN SEE THIS SCREEN, YOU STILL HAVE 00:17:43. "To what?" - Tymon swallowed the end of the word. The drop flicked on and switched to diagnostic mode without being asked. "Confirming local time divergence by exactly seventeen seconds and drift increasing at a fraction per second. Source: below floor level." "That is, below us." Nina slid down the step and walked around the desktop. The floor was of metal truss. Darkness and coldness poured between the cracks. Against the wall, right next to the ladder, was a technical hatch, closed with a wheel. It looked like the hatch to a spaceship, only it was buried in the ground. "Don't open it blindly," - said Tymon reflexively. He was already kneeling by the hatch with a torch, whose beam of light reflected off the metal with a dead flash. - "Check it out." Nina touched the cool steel with her hand. Through the sleeve of her sweatshirt she could feel the material getting damp from the condensing fog. Geometric, hexagonal shapes were forming on the surface of the hatch, as if someone had burned them from underneath with light. Every few seconds, the pattern would disappear, only to reappear a little earlier, like an undone movement. "This is an interference pattern? It's... scrolling on its own?" - she whispered. "The owl registers!" - muttered Tymon, placing the drone on the truss. Two thin arms slid out from its side and sat on the edge like the fingers of a violinist. - "I've also got an optical signal from the fibres above." The fibre optics above the console danced softly, though there was no draught in the hall. The screen trembled. The image from Owl's camera showed something that made Nina forget to take a breath: two silhouettes standing exactly where they were both kneeling. She and Tymon - that's what it looked like - in the same place, only in the frame their hands were already on the manhole wheel. In the top right corner of the video the time was glowing: 00:18:12. "We didn't record it." - Tymon stopped blinking. - "This is not live. This is... later." "Or earlier for someone else," - finished Nina in a colourless voice. - "A drop?" "I'm receiving a phase-shifted looped transmission" - the band hastily reported. - "Origin: chamber under the hatch." The screen flashed once more and then went out abruptly, as if abruptly unplugging. The drop whined a short, inaudible error to others; Nina felt a vibration in the bone of her hand. "Attention," said the Drop already quietly. - "Voice message received with internal routing." "Let go." A whisper developed in the dome, barely louder than the breath of the sea. The voice sounded like her own, only slightly hoarse: "If you're watching this, don't go alone. On the left, around the first bend...". The recording snapped off like a cut cord. Tymon looked at her strangely serious. "We should call a chaperone." "We won't make it if it counts down." - She pointed at the dead screen, as if he could answer. A wave of wind hit from outside, and the dome creaked. The pattern on the hatch accelerated. Hexagons began to appear one on top of the other, like a multitude of glass bees. "Wait," Tymon slipped a technical card into a slot near the hatch wheel. The LED next to it blinked once. - "I'm trying to unlock manually." "Stop," the blob spoke infrequently now. - "Motion detection on the other side. Direction: upwards." Nina and Tymon froze. Through the steel she felt a tremor so subtle she might as well have imagined it. And then the manhole wheel vibrated. First by a millimetre. Then by another. On its own, without their hands. "I didn't touch it." - Nina whispered. "Neither have I" - replied Tymon. There was a mixture of fear and stubborn curiosity in his gaze that she knew like her own pockets. The last remnants of daylight were extinguished in the dome; the fog outside thickened, cutting them off from the world on the surface. The hatch wheel turned a quarter turn and stopped, as if waiting. From the depths came a barely perceptible draught of air and... a whisper. Not in words, more in a rhythm that resembled a heartbeat after a run. The owl beeped, registering something they hadn't seen before. The drop vibrated so hard that she had to squeeze the band with her fingers. The wheel moved once more - more confidently this time - and the hatch began to slowly unscrew towards them.