Astro Equinox pressed three gray fingers to the lab wall and felt the signal before they heard it. A pulse from the sky. Thin, high, patterned. No one else on this planet could hear it. Only Astro's species could, and Astro was the last of them here. For eleven days the pulse had returned at dusk, and for eleven days it had slipped away before Astro could hold it. The lab was built for this work. Dishes crowded the roof. Screens glowed along every wall. But none of the machines could keep the signal. Astro's black eyes scanned each pulse as it arrived, then watched it fade. A rhythm, almost like counting. A message, maybe. Gone in seconds. Astro slammed a hand on the console. "Hold still," they said to the empty room. The pulse did not hold still. It never did. Then Astro saw it. A small device sat on a low shelf, half buried under coils of cable. A sound tracker, left behind by the ones who built this place. Its listening dial had rings of color, dim but whole. Astro lifted it with both hands. The dial warmed. Astro aimed the tracker at the roof dishes and waited. The light outside bled to orange. Dusk. The pulse would come. It came. The wall hummed under Astro's feet. This time Astro turned the dial, matching its rings to the rhythm in their skull. The indicator lights climbed one by one. Astro pressed the capture key. The tracker caught it. For the first time, the pulse did not vanish. It looped inside the device, steady and clean. Astro played it back. The same thin pattern. The same counting beat. Now Astro could study it as long as they liked. Astro laughed, a short sharp sound. Eleven days of chasing, and the sky finally held still in their hands. Then the tracker changed. The rings spun on their own. The captured pulse split into two layers. Underneath the counting beat lay a second sound, slower and deeper, that Astro had never heard inside the live signal. The device had pulled it loose. Astro leaned close. The second layer was not noise. It repeated. It carried its own order, its own shape. The signal was not one message. It was two, braided together. And the deeper one was not calling to the sky. It was answering something already here. Astro set the tracker down slowly. The recording looped on. Somewhere on this planet, something had sent a reply. Astro had spent eleven days trying to hear the sky. Now Astro had to find out what, on the ground below, the sky had been talking to.

The recording looped all night. By morning Astro still could not pull the two layers apart. The counting rhythm sat on top like a wall. Behind it, the deeper message hummed, shapeless and buried. Astro turned the listening dial back and forth. The indicator rings climbed, but the counting beat bled into everything. No matter how Astro tuned it, the real reply stayed drowned in noise. Astro pressed three gray fingers to their temple. The sound tracker was built to catch a signal, not to split one apart. They needed another ear, one that knew machines like this. The lab door slid open. Jeta Halo stepped in, his green skin bright under the screens. He had helped wire half this building years ago, back when Astro first arrived. He carried a coil of cable over one shoulder and did not knock. He never did. "You've been awake two nights," Jeta said. "I can hear that thing from outside." "I can't separate the layers," Astro said. "The counting covers the message. The tracker won't cut it clean." Jeta set down the cable. He bent over the sound tracker and studied the spinning rings. "You're fighting the counting beat," he said. "Stop fighting it. Match it." Astro frowned. "Match it how?" "Feed the counting rhythm back into the dial. If the machine already knows that layer, it can cancel it. What's left is the part it doesn't know." Jeta tapped the polished dial. "You cancel the wall. You hear the room behind it." Astro stared at the device. The counting beat ran in their skull, steady and plain. They had memorized it over eleven days. They could play it back by hand. Astro set the dial to the counting rhythm first. The rings aligned. Then they keyed the capture again, this time holding the known beat against the recording. The two counting layers met. They folded into each other and went flat. Silence, for one breath. Then the deeper layer rose, alone and clear. It was not counting. It was not random. Astro leaned close, black eyes wide. The sound carried a shape, rising and falling in sets. A direction. The deeper reply pointed somewhere, turning in a slow sweep, the way a dish turns to find a source. "It's a bearing," Jeta said quietly. "That's not a message. That's a location." Astro's chest tightened. The thing on the ground was not just answering the sky. It was telling the sky where it stood. Astro played the clean layer twice more. The sweep repeated, steady and exact. Somewhere on this planet, a machine was broadcasting its own position. And now Astro could read it. "I know how to separate them now," Astro said. "But that's worse." Jeta looked up. "Why worse?" "Because now I know it wants to be found." Astro reached for the dial. "I have to reach it before the sky does."

Astro played the clean bearing one more time. Then they heard it. The counting rhythm overhead had changed. The beats came faster now, packed tighter than before. Astro froze, three gray fingers on the dial. Since they split the layers, the sky had sped up. Something up there was closing in. Jeta heard it too. He straightened from the cable coil. "That's quicker than last night." "Much quicker." Astro tracked the beat on the indicator rings. Each pulse crowded the next. "It's tightening its search. It's found the trail." Astro needed to know how close. A faster count meant nothing alone. They had to measure the rate against the bearing. Astro keyed the sound tracker again and fed both signals in together. The rings spun. Numbers climbed, then settled. "Play it slow," Jeta said. He leaned over the polished dial. "Give me the gap between pulses." Astro did. The gap shrank with each loop. Astro held the first count beside the newest one. The difference was plain. The sky signal was narrowing toward the same point on the ground, the exact bearing their device had broadcast. "It's not searching anymore," Astro said. Their voice stayed flat. "It's aiming. The count speeds up as it locks on." Jeta set his palm on the tracker's casing. "How long?" Astro ran the numbers twice. The count would reach full speed in two days. Maybe less. When the beat stopped climbing, the thing in the sky would be on top of the ground device. "Two days," Astro said. "That's when it arrives." The room went quiet under the beat. Astro pressed both hands to the lab bench. Years ago Jeta had wired this building. He knew every panel. Now he only watched Astro, waiting. Astro made the choice out loud. "I can't study this from here anymore. I have to reach the ground device first. I have to get there before the count ends." "You know where it is," Jeta said. "The bearing gives you a line." "A line, not a spot." Astro pulled the sound tracker from its cradle. The device was built to catch a signal, not to carry. But it was the only ear that could read the bearing on the move. "I follow the line and listen as I go. The signal gets stronger near the source." Jeta lifted his coil of cable and looped it over his shoulder. "Then you'll need a hand reading it on the road." Astro stared at him. Jeta had given them the trick to split the layers. Now he was offering to leave the lab too. "You don't have to," Astro said. "You can't tune and travel at once." Jeta nodded at the door. "I can." Astro held the tracker against their chest. The faster count beat on, counting them down. They had their deadline now, and their direction. Astro stepped toward the door.

Astro reached the lab door with the sound tracker clutched to their chest. Jeta Halo stood behind them, cable coiled on his shoulder. The faster count still beat overhead. But the moment Astro stepped onto the threshold, the dial dimmed. The indicator rings slowed. The bearing line thinned to nothing. "The signal dropped," Astro said. They stepped back inside. The rings brightened at once. "It only reads when the device drinks full power. The cable runs to the lab wall. Out there, it dies." Jeta set down his coil and traced the thick cord to its panel. "It can't leave the building. The feed's fixed here." He pressed a hand to the casing. "We can't follow a line we can't hear." Astro stared at the tracker. It was built to sit in a cradle, wired to a wall, not to walk a trail. Without steady power, the bearing went blank mid-journey. The whole plan broke at the door. A woman stepped in from the inner room. Her dark hair hung in a ponytail. Mud marked her boots. Astro had met her once before, when she warned them to leave the signal alone. She crossed her arms now and looked at the dead dial. "You," Astro said. "Me." Jeta Warnson nodded at the tracker. "Still chasing that thing in the sky. I told you to stop." She stepped closer and tapped the casing. "But I know this box. I helped haul it here years back. It ran once on its own cells." Astro gripped the device tighter. "It has no cells now." "It has a port." She turned the tracker in Astro's hands and pointed to a small panel on its base. "Right there. The wall feed hides it. Pull a pack off the lab lights and clip it in. Then the box carries its own power." Jeta Halo was already moving. He opened a floor panel and lifted out a battery brick. Astro unlatched the base panel. Three gray fingers worked the clip. The brick slid home. Astro twisted it until it caught. The dial lit. The rings spun up to full. The bearing line snapped back, sharp and bright, even as Astro lifted the tracker off the cradle and carried it toward the door. Astro stepped outside. The line held. The signal stayed loud. It no longer died at the threshold. "It works on the move," Astro said. Their voice stayed flat, but their hands shook. Jeta Warnson did not smile. "It works. That's the problem." She stood in the doorway. "If you reach that ground device, you'll stand right where the sky is aiming. You'll be on the mark when it lands." Astro looked at the bright bearing line, then down the trail it drew. The count beat on above them, faster now. They had a working ear and a clear path. They stepped out, and Jeta Halo followed with the cable he no longer needed.

Astro stood on the open ground with the tracker bright in their hands. The bearing line pointed straight ahead, strong and sure. But the line ran into trouble. Past the lab's cleared lot, the ground broke into gullies and loose rock. A steep ravine cut across the path. Astro could not carry the tracker over that and keep it steady. One slip would smash the box. The ear would go dark halfway to the source. "The line goes through there." Astro pointed at the ravine. "We can't walk it. Not with this in my arms." Jeta Halo set down his cable coil. His green face tightened as he studied the drop. "Too far to climb. Too steep to carry gear." He crouched and peered over the edge. "We need another way to read it." Jeta Warnson came out of the lab behind them. She still wore her muddy boots and crossed arms. She had warned Astro to stop chasing the signal, but she had not left. In her hands she carried a sleek black cat. Its tall ears curved like open shells, lined with pink ridges. The animal tilted its head and twitched one ear toward the sky. "You won't get the box across," she said. "But you don't need the box." She held the cat out. "This one hears what you hear. Watch its ears. It turns toward the loudest pull." Astro stared at the creature. Its green eyes fixed on something above, something Astro's own kind could sense. The ears swung, settled, pointed the same way the bearing line pointed. "A living ear," Astro said. Their three gray fingers reached out and touched the cat's fur. The animal did not pull away. Its ears held the line. Jeta Halo looked from the cat to the tracker. "We leave the box here, still drinking signal. We follow the cat across the rocks. Light. Quick. We check the box reading when we come back near power." Astro weighed it. The cat could not give exact numbers. But it could point. And it could climb where the tracker could not. They set the tracker down in the lab doorway, line still bright, and lifted the cat into their arms. "Then we go on foot," Astro said. "The cat leads." Jeta Warnson stepped back. She did not smile. "You hear me still. Reach that device and the sky lands on you." But she handed the cat over and let them pass. Astro held the cat to their chest and started down toward the ravine. The ears swung forward, locked on the far ridge. The path across the broken ground opened in the direction those ears chose. The tracker stayed behind in the doorway. From here on, a breathing creature carried the signal, and it was leading Astro straight into the sky's aim.

Astro climbed deeper into the ravine with the cat pressed to their chest. The rocks pitched and shifted underfoot. Then the cat's ears split apart. One swung left toward a tall spur. The other swung right toward a low gap. Both held firm. Astro stopped cold. For six days the ears had always agreed. Now they pointed two ways at once, and the sky device was almost here. "Which one?" Astro whispered. The cat turned its head. The ears did not settle. Above them the sky pulsed faster, a beat only Astro could feel, pressing down like weight. The sound was homing in. Astro had minutes, not hours. Pick wrong and they would climb away from the source while the sky fell on empty rock. Jeta Halo scrambled up beside them, his green hands scraped raw. He had followed Astro from the lab across every mile of this. He looked at the cat and his black eyes went wide. "It's split. Both ears locked." He gripped a stone to steady himself. "The signal's bouncing. One path is the device. One is the echo off the cliff." Astro's three fingers tightened in the cat's fur. An echo. A false return thrown back from the rock wall. The true bearing and its ghost, and no way to tell them apart by ear. Then Astro remembered the trick that started all of this. You cancel the known layer to reveal the true one. "Cover one ear," Astro said. "Block the bounce. The real one stays." Jeta Halo cupped his hand over the cat's left ear, muffling the spur. The right ear quivered, then drove hard toward the low gap and stayed. The cat leaned its whole body that way. "That's it," Astro breathed. "The gap. The echo was the cliff." They turned and ran toward the low opening, the cat straining ahead in their arms. They burst through the gap into a flat basin. In its center stood a squat machine half sunk in the dirt. It was old, older than the lab, built of the same metal as Astro's own skin-tools. A dish on its top turned slow circles. This was the thing broadcasting the bearing. This was what the sky had been answering for who knew how long. Above, the sky tore open with light. The homing signal had arrived. A disc dropped fast, silent, straight down the line toward the machine. Astro stood frozen between them. Then the warning came back, the one from the woman in muddy boots who had pressed the cat into their hands. Reach the device and the sky lands on you. "Down!" Jeta Halo shouted. He pulled Astro behind a rock as the disc struck the old machine. There was no fire. The two devices locked together with a hum that filled Astro's whole body. The braided signal, upper rhythm and hidden bearing, poured out as one clear voice. And Astro understood it. It was not a weapon. It was a call home. The old machine was a listening post, left on this planet long ago by Astro's own kind. It had waited, counting, broadcasting its place. The sky device was the answer, come at last to collect what the post had recorded. The terrible thing the woman feared was only this: whoever stood here when the two met would be taken up with the message. Astro rose slowly. They could step into the light and go home with the signal they had chased for so long. Jeta Halo watched them, his hand still on Astro's arm, waiting. Astro looked at the green face that had climbed every rock beside them, and at the cat that had led them true. The signal had never been a secret to crack. It had been a door. Astro lifted the cat and set it on the ground. They reached into their tool belt and drew out the small recorder they had carried since the lab, its microphone grille catching the light. They pressed record and held it toward the joined machines. The voice filled the little device, every layer, the whole message, saved. Then Astro stepped back from the light. "I came to listen," Astro said. "Not to leave." The disc pulled free and rose, taking the old post's long record with it. The basin went quiet. The sky stilled. The frantic beat that had driven Astro for eleven days was simply gone. Astro stood in the dirt with the recorder warm in their hand and the signal finally decoded, held safe in their own grip. Jeta Halo let out a long breath and smiled. The cat wound around Astro's ankles, both ears calm at last, pointing nowhere, because there was nothing left to find.