Late at night, Zhou Dapao and Qian Hongmei secretly tap into their neighbor Lin Zhengshan's electricity and blast music outside his wall to do square dancing at three in the morning, disturbing the neighborhood. After their power is cut off, the pair make a scene and extort 500 yuan. Just as Lin Zhengshan reluctantly prepares to pay, his college-student son, Lin Yanzhou, returns home. Calmly, he exposes their illegal wiring. Their makeshift connection causes a short circuit that burns out the sound system, and Qian Hongmei's lie about being injured is exposed on the spot. Faced with unreasonable neighbors, Lin Yanzhou stands his ground with facts and sound reasoning.