Lena entered the abandoned weather station as the storm hung over the town like a blanket. She had been walking here for weeks, collecting wind recordings for a project about resonances. In the legends, there was talk of an Echo Gate that answered in just the right tone. Today, Lena was going to see if the legend wasn't an instruction hidden in the noise. At the end of the corridor, an iron door waited, cool, heavy and handleless. The symbol of three arches shone on the panel, identical to the engraving of her grandmother's old key. The key fitted, although the lock sounded low, as if it recognised the owner by name. The phone vibrated; Oskar texted her to wait and not to combine alone today. The storm answered with thunder, so Lena just squeezed the strap of the recorder and pushed open the door. Inside was a circular room with a pendulum, cracked lenses and a copper ring attached to the floor. There were numbers running around the ring and chalk patterns on the walls in a familiar handwriting. Lena recognised the letters from her grandmother's notes: coherence of intention, sensitivity of medium, threshold of silence. Underneath one diagram, someone had added the phrase: "Worlds meet when sound draws a door for them." Lena adjusted the speaker, switched on the frequency sweep and searched for the tone that trembled in her bones. At 432 hertz, the copper trembled and a powder of chalk sprinkled from the ceiling. The air thickened, the ring began to swirl with the image, as if filled with glassy darkness. Stars flashed in the reflection, which did not move with the earthly sky, but flowed against it. She heard two heart rhythms: her own and a second, alien one, pounded out as if by water. On the surface of the darkness appeared a shoreline, two moons, and a silhouette standing in the shallow water. The figure raised its hand as if measuring the distance, then flexed its fingers in invitation. The phone vibrated again; the notification flashed: "Don't come in, Lena, it doesn't end where you think." A chill blew from the ring, the screws turned of their own accord, and the pendulum hung horizontally, like a pointer. On the other side, something said her name in her grandmother's voice, and the taffy swelled like the skin of a drum. Lena drew in a breath, took a step and suddenly a hand slipped out of the darkness. The skin on her shoulders turned pale from the frost and the smell of salt, even though she was far from the sea. On the ring wound she discovered three fresh scratches, like claw marks, leading towards the centre. There was a rumbling sound behind her, perhaps footsteps on the stairs, perhaps just the echo of the storm. Her hand trembled in the gloom, as if waiting to be touched, and the stars inside darkened. Lena raised her hand, ready to synchronise her breathing with that pulse, when something banged on the door. The lock whined in a tone she knew from her childhood, and her grandmother's voice whispered: "Just once."