Undercover Returns The Crime Thriller About a Police Officer's Hidden Life.The story follows Detective Diamond, an undercover agent who has infiltrated the drug cartel. Over the years, he has collected evidence and helped dismantle a dangerous organization. Having earned the right to finally return to his police unit, Diamond is assigned another mission when a new criminal gang emerges, gaining strength at an alarming rate. With every passing day, he must continue the undercover life in order to help bring the perpetrators to justice.Stars Zhang Jiayi, Lin Yushen, Liu Aijun, Di Tianlim, Fu Jing, Li Qiqi, Tang Zhenyi, Zhang Chengguang, Yang Yu Ting, Wang Pan, Li Yanming, Yao Zhexi, Shi Tingao, Zhang Jingwei, Yang Lei, Zhu Yuner, Deng Kaiyu, Mann Lim Lian, Zhou Yi.