Village tyrant Wang Dafa forcibly occupies the ancestral burial ground and private land belonging to Zhang Hao's family, demolishes their gravestone, and builds a luxurious villa. Zhang Hao quietly sells his property and constructs a lighthouse on his family's legally owned eight-square-meter plot, right next to the villa. Equipped with reflective surfaces, powerful speakers, and deep foundations, the lighthouse becomes his weapon of precise, entirely legal retaliation. When a devastating mountain flood strikes, Wang Dafa's cheaply constructed villa collapses. Reduced to begging on his knees, he pleads with Zhang Hao to save him. After rescuing him, Zhang Hao demands repayment of his debts, eventually leaving Wang Dafa a beggar. The lighthouse becomes an unshakable symbol of protecting one's home.