In Philadelphia, the United States, there is a homicide investigation team. The cases they face are not recent, but old cases from several years ago or even more than ten years ago. Such cases are particularly difficult to investigate because they happened a long time ago, the parties involved are difficult to find, and all kinds of criminal evidence have almost disappeared. Such homicide cases are vividly called "Cold Cases". Lilly Rush, as the only female detective in the Philadelphia Homicide Investigation Department, is the absolute core figure of this TV series with the theme of investigating old cases. Her calmness, alertness, and her slender and pale face have left an indelible impression on the audience. This TV series, which has been broadcast by CBS since 2003, still stands out among many TV series with crime themes with its unique charm. Cold Case is different from CSI in that it presents the criminal investigation process to the audience like a documentary, and it is not supported by many cutting-edge technologies today. In this drama, there is almost no scene similar to "CSI Season 8" and other dramas about using high-tech to analyze corpses to find clues. Her unique charm lies in that, with Lilly's tenacious character, she and her partners always try their best to find those parties who are still alive, so that those who live in the shadow of the past can recall the tragedy that happened in the past in either relief or painful struggle, bringing the audience to the different world decades ago, and allowing the real murderer to emerge little by little in the different memories and confessions of the parties. And every time the truth is revealed, the audience will find an incredible ending, which may be tragic, angry, or helpless. But no matter how incredible the crime that happened that year was, the passage of time will eventually soothe people's sadness. Cold The whole play of Case is filled with a strong nostalgic color and a touch of sadness, or a kind of female warmth, which makes you gradually moved by each story, leaving some touches in your heart. The most touching part of the whole play is at the end. When the real murderer was brought to justice, Lilly always saw the people who died that year standing on the opposite street corner, smiling at her, as if they really thanked her for redressing the injustice. At that moment, even the hardest heart will be deeply moved.