The last week of the holiday smelled of algae and tar on the pier. Zosia knew every creak of the planks, but today something was different. A green bottle swayed between the tyres of the bumpers. There was a cork stuck in the neck and a wad of paper glittered inside. Zosia called out loudly to her cousin. "Maks! Come here quickly!" The boy came running in, still in his yellow kapok. "Fish scales again?" he snorted. "No, the map," Zosia said and lifted the bottle like a trophy. They unrolled the paper on the rope box. The ink was faded, but the marks could be read. There was Owl Island, an abandoned lighthouse and an eye symbol. It led to a door at the base of the cliff. "Are we sailing?" asked Maks, and his eyes were already shining. The sky was smooth as glass, but behind the reeds something rustled, as if someone was listening. Zosia nodded. "Let's take the oars and the torch. And nothing to anyone." The boat cut across the silent taffrail, and the diver whistled individually and disappeared among the waves. As they passed the cove, the lighthouse blinked with a single light. It had been dead for years, so Maks stopped rowing. Maks whispered: "Did you see that?" and Zosia clenched her teeth: "Don't turn back." By the old pier, the wood was dark and sticky with salt. For a moment the boat scratched against the stones, as if something was holding it by the bottom. Stairs led up to the cliff where the map marked the eye. The door was metal, with an owl symbol stamped on it. They put their fingers in the crack and pushed together. The lock rattled and moved a hair's breadth away. There was a chill blowing from inside and a smell of rust. Suddenly there was a second splash of oars from the water behind them, regular and getting closer. Maks whispered: "After all, nobody knew..." Zosia raised her torch as the lantern light came on for the second time.