A cataclysmic event causes a man, who dreams of winning the lottery, to become stranded on an island with his co-workers.

A scientist uses his invention – the “Menger Sponge” – to capture the energy of a dead child’s spirit in an old building. In trying to determine why the energy of the ghost does not dissipate, the team discovers the identity and the dramatic story of the boy.

In this prequel to Mou gaan dou (2002), Chan Wing Yan has just become an undercover cop in the triads while Lau Kin Ming joins the police force. Both the triads and the police find an enemy in a rival crime boss.