The wind carried dry leaves down Silver Maple Street, which rustled as if whispering secrets to each other. The streetlights shone warmer than usual, and the smell of baked apples and cinnamon wafted into the sky. Pumpkins with cut-out smiles twinkled in front of the houses, and costumes glided along the pavements: witches on trampoline broomsticks, pirates in trainers and cardboard knights. Lena fixed a headband with cat ears on her head. They were black and glittered with silver glitter, as if someone had sprinkled them with stardust. Oskar carried under his arm a telescope he had made himself from a poster roll, because he had decided to be an astronomer that night. In between them, Pączek, a white mutt in an orange jumper shaped like a pumpkin, trotted along. His tail was wagging so vigorously that it looked like a fan. - If anything unusual happens today, Pod will be the first to sense it,' muttered Oskar, glancing at the dog. - He has a nose like a radar. - And Grandma said that the town breathes differently on Halloween - added Lena in a whisper. - And that the old lantern by the maple tree can talk. It was this lighthouse that they had heard about for as long as they could remember. It stood at the very end of the street, right in front of the park. Cast iron, with a scratched ball and intricate vine leaves cast in the metal. Grandma Basia called it the only lighthouse that still remembered the days when horses pulled sledges along this road and when, in winter, the light reflected in the snow like a mirror. - I wonder what she could say? - wondered Lena, looking into her bag of sweets. Oskar shrugged his shoulders, but his eyes flashed with curiosity. After all, it's not every day you hear about talking lanterns. They both hopped from pavement to kerb and back again, knocking on more doors. Neighbours treated them to chocolate bats, sugar bonbons and even warm honey fudge. Doughnut would get a piece of dried apple each and behave like a gentleman, sitting down politely when someone wanted to pet him. When they arrived at the house of Mrs Niteczka, the dressmaker, Lena took her own pumpkin lantern out of her bag. It was not too heavy, with star-shaped eyes carved into it. Her grandfather had helped her yesterday, teaching her how to cut out the designs safely and how to grease the edges so the pumpkin wouldn't wilt too quickly. Inside, instead of a traditional candle, was a tiny battery-operated light, which Donut was relieved about, as the fire made him sneeze. - What a miracle! - Mrs Niteka clapped her hands. - You deserved something special. She handed them a paper bag with dark green leaves. Lena slipped it inside her bag and suddenly felt something hard under her fingers, with a shape that did not resemble a candy. She took out a small piece of paper, jagged at the edges, as if someone had torn it out of an old notebook. On the paper, in ink the colour of ink from long ago, was a short sentence: 'Light me up at the Old Maple'. - Who put it in? - Oskar lowered his voice as if the piece of paper could overhear them. - After all, we just got here... - Lena looked over. On the porch, Mrs Thread was untangling a web of yarn that the wind had hung from the railing. In the street the bustle was mixed with giggles. No one was looking at them. Pod sniffed the note so vigorously that he sneezed. Then he raised his head and squeaked quietly, as he always did when something irritated or intrigued him. - 'It's probably a joke,' muttered Oskar, but it sounded more like a request to the world for an explanation than a certainty. - Or an invitation - Lena squeezed the lantern. - To the lantern by the maple tree. They made a few more houses, but each 'trick or treat' sounded louder and louder, as if the card in the bag weighed more than the bag of sweets. Finally, they turned into a narrower street ending in a small square. Here it stood: An Old Maple, a tree with a trunk so wide that the two of them would not embrace it, with branches spread out like the arms of a giant. At its feet was a lantern. Today it shone faintly, as if hesitating whether it should at all. The wind died down as soon as they entered the square. Above them stretched a sky dotted with glassy stars, and from afar, from the old town hall tower, came the sound of a clock. One, two, three... Oskar counted in his mind. Twelve. And another, quieter, as if in a dream. - Did you hear that? - Lena looked at her brother. - Thirteen? - Maybe an echo... - Oskar swallowed his saliva. - Or someone made a mistake. Beneath the lighthouse, the cobblestones were different from the rest. The stones were smooth, polished by hundreds of footsteps, and formed a pattern they had never noticed before: a circle with tiny zigzags, like waves spreading across a pond. On the cast-iron base of the lantern, right next to the bolt, someone had scratched out a small mark - a star similar to that of Lena's pumpkin eyes. - 'It could be a coincidence,' whispered Oskar, but he already knew they wouldn't leave without checking. Lena slipped her finger under the metal switch of the pumpkin light and pressed it. The light came on with a soft, warm glow. And immediately it changed shade. Gold turned to amber and then to a greenish light that was neither cold nor hot, just... different. The budgie cocked its ears, squatted down and began to wag its tail, but cautiously, as if weighing whether this was the moment to rejoice or still to be alert. - Oi... - Oskar leaned over. - Do you see that? The shadow of the pumpkin lantern was not falling as it should. Instead of briefly, towards Lena's shoes, it reached sideways, deep into the circle of stones. It moved, as if a draught was pulling it underground. After a moment, a thin trickle of light began to creep across the cobbles, drawing a line that stopped at a small metal flap between the stones. Until now they had thought it was an ordinary sewer grate. Now, however, it looked like something that had been waiting for a long time. The lantern above their heads flicked on and shone cooler, at the same time as Lena's pumpkin glow. A shy glow drifted onto the maple tree, just enough for them to see that in the bark of the tree someone, long ago, had scratched out letters. Almost obliterated, but still legible: "If you seek me, seek the light". - Who had written it? - Lena touched the bark, feeling the unevenness of the letters under her finger. - Perhaps a lighthouse keeper? - Oskar looked around as if an old man was about to emerge from the shadows with a bunch of keys and a lantern on a pole. The bud raised his paw and growled the way one growls at one's own reflection in the mirror: not confidently, but firmly. Then he walked over to the metal flap and tapped it with his paw. Something underneath responded with a dull, single knock. Lena and Oskar held their breath. One knock. Then a second, a tad louder. The green of the lantern in the pumpkin flared brighter, and the shadows of the maple branches twisted on the ground in a whirling, short dance. - 'Maybe it's a frog or a hedgehog? - whispered Oskar, although he didn't sound convinced. - 'Hedgehogs don't knock,' replied Lena just as quietly. The flap moved a millimetre, as if something from underneath had slipped a fingernail underneath it. The knots of grass around it twitched. The bud took a step back, but did not look away. At the base of the maple tree there was a cool breeze, the kind that reminded one of opening the cellar door on a hot day. A bell rang from the town hall. Once. Just once, although it had not yet been a full five minutes. Lena and Oskar looked at each other communicatively. Lena raised the pumpkin lantern so that its glow fell directly on the metal. The light began to pulsate, as if responding to the heart hidden beneath the cobblestones. - On the count of three - Oskar knelt down, resting his hands on the edges of the flap. - One... At the same instant, a distinct whisper rang out from deep beneath their feet, a whisper that knew their names and sounded as if someone was standing on the other side of a thin wall of stones. The flap jerked upwards, as if an invisible hand had pushed it from within, and the green light, in one short wave, streamed straight into the darkness of the opening fissure.