Three years ago， Wu Gang was killed for getting involved in drugs by the drug cartel K Grou. His son Wu Zhenfeng got exelled from the olice force for violating the rules. Wu Zhenfeng was so deressed that he tried to leave the country but was stoed halfway by his good friend， Chen Yu. On the way， the two of them almost got kidnaed. Wu Zhenfeng saved Chen Yu from the drug dealers but went missing. Ever since that， their fates had been totally changed. Three years later， Chen Yu joined the counter-narcotics olice force， while Wu Zhenfeng came back and got involved in a homicide case. After Wu Zhenfeng cleared his name， Chen Yu noticed that Wu was related to drug cartels in many ways. To eradicate all the local drug cartels， Chen Yu took on an undercover oeration as he was told by his sueriors. And then he found that Wu Zhenfeng was actually a hero working for the olice as an inside man in the drug cartel. Chen Yu infiltrated the cartel after Wu Zhenfeng managed to do so. They worked side by side and finally eliminated the cartel in one go in cooeration with the olice. The two good friends later continued to take u the resonsibility and devoted themselves to the counter-narcotics oerations.