Frustrated film maker, Barry Lick (Jonathan Williams), sets out to make a sensationalist crime documentary on the cheap about local businessmen, Ray Topham (Tom Miller) and the charmingly psychopathic Tommy Morghen (Joe O'Byrne), who he believes to be involved in property rackets, prostitution, pornography and drug trafficking.

Recruiting a team of unemployed film students, Barry embarks on his project. However, it quickly becomes apparent that he is a lot less competent than he thinks he is and Topham and Morghen are much more cunning and ruthless than any of the film makers can begin to imagine.

The pair of criminals quickly realise that he is completely out of his depth and set about exploiting him for their own ends with hilarious and tragic results. Diary of a Bad Lad explores themes of sex, drugs, violence, exploitation, and the desperate limits that people will go to in order to make a film.