Gangster leader Fung is sentenced to life imprisonment and is very down as he fails in his appeal. Influence by his father, Fung's son Wai joins the gangster. While in jail, touched by the Father, Fung becomes a believer and tries to guide Wai but in vain. Soon, Wai gets behind bars. Fung is so regretted that he makes way to preach at the jail for youth to see his son. Wai is moved and promises to start a new life. Since then, Fung always preaches among the young criminals and is reputed as "The prison preacher".