Ross explores the dark heart of the country's ferocious Number's Gang that thrives on over-crowded prisons. In Pollsmoor High Security Prison Ross experiences the terrifying sensation of incarceration among vicious murderers, rapists, and violent armed-robbers.

Ross's examines Middle America's gang culture with a visit to St. Louis, Missouri; where he takes a look at how an average Midwestern municipality where in a population of 342,000 people, there are around 380,000 guns – and many of these are in the hands of gang members.

Ross infiltrates Moscow's vicious Neo-Nazi gangs to discover who is behind a recent wave of racist attacks and hate crimes; and uncovers the extent to which these National Socialist groups are gaining power in the country.

San Salvador Ross wastes no time immersing himself in the dangerous world of the Mara Salvatruchaor MS13 gang. "El Salvador has a level of violence that far exceeds any other country I've been to," says Ross, "there are on average 11 murders a day in a country with a population smaller than London."