There are new clues to the huge unsolved drug trafficking case from five years ago. Former narcotics officer Yan Jin has gone undercover to find the culprit who murdered his good friend. Along the way, he falls for the kind and forthright coffee shop owner Ji Xiao'ou. However, he seems to be keeping too many secrets from her.
Meanwhile, Zhan Yu who has unrequited feelings for Ji Xiao'ou becomes increasingly jealous. When he is suddenly killed, Yan Jin becomes the prime suspect as Zhao Ting Wei launches an investigation. Yan Jin finds himself caught up in the lies as he tries desperately to complete his mission.