The Seventeen Seconds of the Tide

In a fishing village, there is a rule: anyone who hasn't climbed the tower by the age of thirty-five will be taken away by a boat at low tide. In three days, he will turn thirty-five... He is the tide recorder, and for fifteen years he has done only one thing: write down the number when the tide recedes. But his master left another rule: after the tide recedes, there are seventeen seconds of residual tide, during which the water temperature is abnormal, and something in the mud is awake. The master left fifteen years ago, leaving only a tattered 'Supplementary Record', a shell that never cools, and a sentence written on the back of paper: 'Don't touch it a second time.' The red cotton thread on his wrist heats up at night, as if something is pulling it toward the sea. There is a patch of warm mud on the beach that only burns when he steps on it. There is a black spot on the sea that never approaches, yet never disappears. He has only three days left. In three days, he must figure out: why didn't the master cut that thread back then? He said, seventeen seconds is not enough to count to seventeen. But that's his business... — Description from novelcodex.org