Lena was familiar with the sound distribution of the old depot before she knew its dark history. The metallic clatter of the gates sounded like a whisper as the wind swept over the rusty tracks. That evening she came alone, with a rucksack, a torch and a thin notebook from her brother. She promised herself that she would only come back here once she was really ready. Olek had disappeared a year ago during a September storm, leaving only a photo and a notebook. He had scrawled a threshold sign on the first page, with a brief warning underneath. Don't close the door if you hear a train that isn't on the timetable. Lena knew every line of his handwriting, but she didn't understand this one sentence. He was always looking for passages, recesses and gaps that others didn't notice. The notebook led her straight here, to the technical platform marked Track Zero, right next to the hall. She was to stand at twenty-two seventeen, turn off her torch and whistle twice. When the clock, stopped for years, clicked silently, Lena took a breath and whistled. The sound didn't fly into the night; it curled up, slanted and returned to her lips. That's what the notes said, marginalia full of arrows and thick dots like constellations. The track shone like glass and the air above it wrinkled like water. From the depths of the hall came the inverted whisper of a megaphone, crippling announcements retracting syllables. Gravel squeaked underfoot as the letters T and Z on the board changed colour. She had to touch the sign, though her hands trembled and smelled of dust, ozone and grease. Overhead, the rope from the pantograph swayed, resembling a stationary compass pointer. The phone vibrated with a brief question from Michael, but Lena pushed it deeper into her pocket. An oblong window opened in the shimmering track, and behind it another city trembled. The towers were leaning the wrong way and the lanterns grew like water plants. She heard a third whistle, not her own, recognisable as a breath, and bit her lip. A hooded shadow shimmered on the smooth surface, lifted her hand and touched the glass. Reflections flowed in the glass of those tenements, as if time had a different density and flavour. A chill pierced his fingers as the surface receded, plastic as ice in the spring sun. The hall trembled, the pointer moved a minute, and the track below began to purr low. The shadow on the other side placed a hand on her palm and whispered her name. And then the rumble of invisible wheels came from the darkness of the tunnel, faster and faster, closer and closer. Dust rose underfoot, formed into lines, as if someone were drawing a track with a finger.