Former Macao police captain Liang Jinghui has left the force due to concerns over his mental health. He now works security at a hotel, but spends his spare time trying to put together evidence to solve a three year-old case that left one of his colleagues dead and a criminal mastermind free. When he stumbles across a cyber finance company trying to create a new financial platform in Macao, he smells a rat. He resigns from his security job and gets hired by the heads of the "Sim coin" company - Simon and his alluring partner Guo Wanjun. The keen-nosed Hui sniffs out a conspiracy that could also lead him to close the case that haunts him.