With a severe rainstorm warning looming, villagers Lao Zhao and Lao Li from Xiaba Village are locked in a bitter dispute over half a meter of land on a barren riverbank, seriously obstructing the village's only flood discharge channel. Surveying engineer Lu Hang returns to his hometown and stumbles upon the confrontation. Within three days, he must use modern 3D surveying technology and old maps from the archives to accurately redraw the boundary and help the village director clear the obstruction and eliminate the danger. However, historical maps and modern coordinates have deformation tolerances, while his maternal great-uncle Lao Zhao, driven by selfish interests, secretly worries about the results and attempts to interfere with the calibration. Can Lu Hang find the original benchmark stone monument buried deep in the hills behind the village in time, settle the long-standing feud between the two families with irrefutable data before the flood peak arrives, and protect the peace of the entire village?