On a hot evening, Lena received a parcel with no return address, wrapped in jute string. Inside lay a brass key and a hardcover notebook that smelled of dust. On the key hung a tin with a stamped inscription: Hromada Observatory, north dome, old. The notebook had belonged to her grandfather, a meteorologist who had disappeared three years ago during a spring storm. There was only one sentence on the first page: the Light Chamber works, but it requires bold eyes. Lena took her leave and set off for the mountains, although her heart tapped like an erratic metronome. The observatory stood high above the village, with three domes and a jagged fence full of rust. Mrs Sophie, the only caretaker of the place, handed her a thermos and warned her in a whisper. - Don't go into the north dome after dark, the current can be capricious and the echo plays tricks. Lena smiled kindly, but the notebook was weighing down her backpack like a stone with questions. Between sketches of clouds and equations she found a map of corridors and a note: New moon look for, but don't open door full. The moon was going down and the sky had the look of a raw, unpromising sheet over the ridge. In the evening, Lena entered the north dome, criminating puddles and silent bands of dust. The generator beeped in surprise with a harsh whirr, lighting up narrow strips of light across the grey plaster. A shortwave radio waited on the table with a note taped to it: Channel 7, interval five. When she switched the device on, she heard a series of short beeps, as if someone was dictating numbers from a distance. She wrote them down quickly and compared them with her grandfather's notebook; they matched the dotted lines. Behind the wardrobe she found a loose panel, and underneath it a round sun-shaped socket with the centre torn out. The key fitted perfectly; its teeth entered the socket with a quiet click, as if it recognised the house. At the same instant, the floor vibrated and a blurred outline of a circle was outlined in the wall. A short, rhythmic breathing came from inside, which could have been the wind or someone tired of climbing. Lena shone her torch and saw a drawing of a constellation, scratched with a fingernail next to the sentence: Breathe slowly. - Hello? - she called out, feeling the cold from the dome mix with the warm blast from under the door. The radio beeped again, this time more clearly, as if someone had said her name and then interrupted. - Grandpa? - she whispered, though it sounded childish and far too late to turn back now. Outside, it began to sprinkle, the metal plating ringing in an even, steady rhythm across the structure. A deep purr ran throughout the dome, like a transformer starting up, and light spilled out in thin rings. Points lit up on the walls, laying out a map of the sky she knew no atlas could provide. The radio clicked, Ms Sophie's voice spoke nervously: - Lena, come down immediately, the line of storms is heading straight for your hill. The lock on the circle turned a hair's breadth on its own, and a strip of milky glow flowed out from under the door; someone on the other side had just grabbed the mechanism.