The lighthouse on Owl's Cliff blinked differently than usual that night. Instead of an even, calming rhythm of one-two, one-two, its light interrupted the fog unevenly, as if someone behind the glass was giving signals with a torch. The sea was swollen after the day's storm, and the waves slammed against the wet boulders with a sound you could feel in your ribs. - 'Count it again,' asked Cuba, putting his hood deeper over his ears. - 'Long, short, short, pause, long, short, short. Hania was eleven years old, with a checkered notebook and a patience for things that to others seemed too quiet, too distant or too small. Ever since she became a Girl Scout, she had been practising the Morse alphabet, tapping out dots and dashes on her school desk. Now her finger was sliding across the salt-slippery pages, writing down sequences. - It's not a coincidence,' she muttered, squinting. - It's a pattern. See: two dashes, a dot, a dot... and then a break again. And then something like... a number? Or a letter. - 'Mr Bogdan said that the lighthouse can go crazy after a thunderstorm,' Kuba said, but his voice betrayed that he also felt this tingling in the back of his neck. - But to make it so... like it was talking to someone? In the town below, the narrow streets smelled of algae and tar. On the fisherman's pier, tarpaulins flapped like wings and people clambered around the nets, loud and sedate as ever after a storm. Only the lighthouse keeper's house, pressed against the slope like a white shell against a stone, was dark. Mr Bogdan had not shown up in the harbour for two days. "He went to see his brother," - said the lady from the bakery. "He fell asleep". - stated someone else. But none of the adults looked up to the top of the cliff as often that evening as Hania and Kuba. Hania wrote down the last dashes and dots. Her heart was pounding faster not because of the wind. - It's forming a word," she whispered. - "NO..." - she paused as the lantern blinked too fast again and the fog tore like a curtain. - "NO SCH..." - Don't come down? - prompted Cuba, swallowing his saliva. Before she had time to confirm, the light was covered by a cloud, and a protracted moan came from the distance. It seemed to be the wind singing through the steel railings, but the melody was too even, too... deliberate. - 'Let's go,' said Hania before she could be frightened by her own 'no'. - 'We'll see what's going on up there. Before someone turns off the lighthouse and the bay gets really dark. They took a torch, some lemon candy, which Cuba always carried for a worse mood, and Hania's notebook. The path to the cliff was narrow and strewn with pebbles that escaped from under their shoes like silverfish. On the way they passed sea buckthorn bushes with berries like little oranges and heard snakes snorting somewhere in the reeds, awakened by the sound of the waves. - Did you know there are supposedly caves in this rock? - said Kuba in a whisper, as if someone could overhear them. - Old ones, carved out by the Germans. The history teacher said they lead under the lighthouse. - Rumours - cut off Hania, but her gaze reflexively hung on the hollow cliff face where the wind painted dark shadows. - Besides, if there were any tunnels, they would have collapsed long ago. - Or someone would have... - Kuba began, but cut off as something rustled just above their heads. With a shriek a seagull swooped out, scattering tiny droplets of water. The children laughed nervously, pretending it was just a bird. The door to the lighthouse keeper's cottage was shut, and the padlock - the heavy brass one that Hania always remembered - hung helplessly on a nail just inside. Inside it smelled of cold, old soap and oil. On the table was a mug with a round stain of tea and an open calendar with various scribbles. For one day, yesterday, someone had written in thick pencil: "DON'T LIGHT UP", underlining twice. - 'I don't think this is a funny joke,' muttered Cuba, fumbling in his pockets as if he could find an explanation in them. - Why would he write that? And where is he? Hania didn't answer. Something was drawing her towards the staircase leading upstairs - narrow, metal, wrapping around the inside of the tower like a spring. Each step had a number hammered into it. One, two, three... The sound of her boots echoed through the void and seemed much louder than it should have been. When she touched the handrail, she felt dampness and tiny grains of salt under her fingers. - Can you hear? - she whispered after a moment. From above, from under the lamppost, came an even, scratchy sound. A tapping. One, two, pause. Once, pause. Twice. Hania closed her eyes, as she always did when she counted: dot, dash, dot.... - It's the same rhythm - Kuba's exhalation was warm and fast. - As if someone... as if someone was tapping on the glass. On the thirteenth step, the stairs crackled differently under their weight. Wood, not steel. Someone had once replaced a step here, but had done it crookedly. Hania hesitated for a moment. In her notebook, somewhere between a sailor's knot pattern and a plan of the school playground, was a page with the words "NO SCH...". She looked up. The tapping had stopped. - 'At most, we'll come down quickly,' she whispered to herself, and moved on. The lantern was a machine from another era. The lenses in the huge glass eye rotated majestically, scattering white blades of light across the sea. Inside, it smelled of iron and grease, and the air had the taste of electricity. Streaks of light crept across the floor like silent sea serpents. On the windowsill by the window lay a notebook - not Hani's, but similar: thick, checked, with yellowed corners. On the first page: "Candle diary". Someone had typed in the hours and noted when the bulb was changed, when the glass was cleaned. The last entry was irregular, written in a trembling hand: "21:17 - blinks. 21:23 - pattern? 21:31 - if it's for me, then...". Further on, the ink smudged into a blot. - Hania... - Cuba pointed with his finger to a metal grate in the floor near the wall itself. Beneath it, in the darkness, something glinted. As if there was another, narrower space inside the tower. A tunnel? A technical space? The grille was closed with a lock, above which someone with a trembling hand had scratched out the number 13. - 'This doesn't look like a joke,' said Hania, but she couldn't take her eyes off the cold flash below. Before she could take a step, something clattered against the glass of the lantern just above their heads. One. Two. A pause. One. Two. Three. - It's not the wind," said Cuba unnecessarily. Hania pressed her fingers against the cool glass and almost immediately withdrew her hand. The glass trembled gently, as if someone on the other side was resting their forehead against it. For that moment, a white light cut through the fog and stopped for a split second, illuminating something on the water. Something long, dark that swam against the waves, like the shadow of a very tall figure walking near the very bottom. - Did you see it? - Hania barely touched her brother's shoulder. - 'No... I mean... yes. But it could have been a buoy. Or... - he broke off as a new sound came from inside the tower. Not a knocking. A quiet clacking, as if a key had hit metal. - 'Someone's here,' said Cuba with a noiseless mouth. Hania already knew it. Under the grille with the number 13, something moved, and then a slender brass stem slid out of a narrow gap. A key. It dangled on a frayed string and its teeth were worn down from use. - He... someone is handing it to us - Hania surprised herself at how calm she sounded, although all the time she had the impression that someone's gaze was gliding down her neck. Kuba looked at her, at the key, at the grate. - Don't open it,' he said quickly. - After all, we don't know what's down there. And that writing on the calendar. And that 'don't go down'.... Hania bit her lip. Her heart was pounding like a hammer in a tin bucket. But that sound - that insistent rhythm from above, those dots and dashes - were no accident. Someone was trying to say something. And someone else, inside the tower, was literally pushing the key under their noses. - I'm just going to have a look,' she whispered. - I'm not going down. I'll put the key on, see if it fits. If there's something wrong, I'll lock it right away. Cuba did not answer. He stood very still, as if he too had become part of the mechanism that just tick-tock, tick-tock measured the heartbeats of the lantern. Finally, he nodded, one time, slowly. Hania knelt by the grate. Up close she could see that the number 13 was not scratched out with a knife, but with a nail, nervously, as if someone's hand was shaking. She pressed her fingers against the cool metal. The brass key was heavier than it looked. It fit the lock perfectly. The teeth hit the grooves with such a satisfying click that for a moment Hania forgot to breathe. - 'Hania,' whispered Kuba. - 'The light... The beam from the lantern shifted, illuminating the sea again, but this time it didn't reflect off the mist. It stopped, hesitated, as if something had sucked it in. The tower grew half a tone darker. The tapping above their heads accelerated. Someone behind the glass clearly, emphatically tapped out: K-T-O-? - Done,' said Hania, feeling something vibrate inside the lock. - Attention. She turned the key. The lock gave way with a groan that rolled down the stairs like a bullet. At the same instant, the handle to the lighthouse moved of its own accord with a quiet, disturbing clatter, and the light in the tower trembled like a candle flame on a draught... and suddenly the entire summit of Owl Cliff was plunged into thicker darkness.