Ip Man's peaceful life in Foshan changes after Gong Yutian seeks an heir for his family in Southern China. Ip Man then meets Gong Er who challenges him for the sake of regaining her family's honor. After the Second Sino-Japanese War, Ip Man moves to Hong Kong and struggles to provide for his family. In the mean time, Gong Er chooses the path of vengeance after her father was killed by Ma San.

He was a writer. He thought he wrote about the future but it really was the past. In his novel, a mysterious train left for 2046 every once in a while. Everyone who went there had the same intention.....to recapture their lost memories. It was said that in 2046, nothing ever changed. Nobody knew for sure if it was true, because nobody who went there had ever come back- except for one. He was there. He chose to leave. He wanted to change.

Chan Wing Yan, a young police officer, has been sent undercover as a mole in the local mafia. Lau Kin Ming, a young mafia member, infiltrates the police force. Years later, their older counterparts, Chen Wing Yan and Inspector Lau Kin Ming, respectively, race against time to expose the mole within their midst.