Across the world millions of people are members of street gangs. In groups they fight, stab, rob, rape and murder anyone who isn't one of their own. And when rival gangs meet - what you get is warfare.

Ross Kemp infiltrates these groups of criminals to discover who they are, what makes them tick and what the law is doing to curb their criminal activity. On his harrowing journey he:

* meets murderous members of the Number gang in Pollsmoor Prison in Cape Town

* crosses paths with Maori criminals in New Zealand

* gets shot at in Rio

* is set on fire as an initiation test for Russian Neo-Nazis

Ross Kemp manages to get close to the world's most violent street gangs: he's streetwise enough to earn their trust and get them to confide their innermost secrets. It's a wild ride - and not for the faint hearted.