Eighteen years ago, on an ordinary night, seven teenagers, such as Lin Langsheng, Shen Jingyi and Xie Jiafu, who grew up in the estate, quarreled with the villager, Hu Qisi. After the fighting and chasing in the night, Qi Si fell in the pool of blood and died. They ran into a catastrophe and decided to bury the body, praying that this secret will never be known. Over the past 18 years, they have all grown up and established their own careers and lives. However, Qi Si's body was discovered and the secret of that year was unearthed. Inspector Ruan Lijin of the serious crimes team took over the homicide case and gradually revealed the truth.