San Pedro is Bolivia’s most notorious prison. Small-time drug smuggler Thomas McFadden found himself on the inside. Marching Powder is the story of how he navigated this dark world of gangs, drugs and corruption to come out on top.

Thomas found himself in a bizarre world, the prison reflecting all that is wrong with South American society. Prisoners have to pay an entrance fee and buy their own cells (the alternative is to sleep outside and die of exposure), prisoners’ wives and children…