After three years of fishing without catching a single fish, Chen Bei receives a mysterious warning from a homeless man by the river: if he returns home before seven that evening, he will meet a deadly fate. Just as he begins to doubt the man's words, he hooks an enormous fish and excitedly carries it around, showing off his catch. Strange distress messages and repeated calls from his wife urging him to come home soon follow. When he finally arrives home late, he discovers a murder has taken place, and he becomes the prime suspect. Relying on the complete eyewitness testimony and physical evidence preserved by his fishing trip, he fights to prove his innocence. As the investigation deepens, layer upon layer of conspiracies hidden beneath his marriage and neighborhood gradually come to light, while a mysterious force lurking in the river holds the key to the entire story.