A man with a low IQ has accomplished great things in his life and been present during significant historic events—in each case, far exceeding what anyone imagined he could do. But despite all he has achieved, his one true love eludes him.

In 1927 Hollywood, a silent film production company and cast make a difficult transition to sound.

When the Goddess of Happiness tosses the Longevity Monk and his disciples out of heaven (because the Monkey King tried to attain immortality), the Monkey King is reincarnated as the Joker. He now spends his time chasing two jealous women. When one of them is dying, the Joker goes back in time in an attempt to save her.

This sequel to "Pandora's Box" continues director Jeffrey Lau's adaptation of the Buddhism saga "Journey to the West". Stranded five centuries in the past, Joker Monkey King must battle a variety of monsters, seductive women and super-powered villains to save the dying Pak Jing-Jing.

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.