The UK prison system has a rich and thriving black market, with its own micro-economy based on tinned fish. Drugs, food, iPhones, and games consoles are everywhere – if you know where to look (and who to ask). VICE speaks to former prisoner and filmmaker Chris Atkins, author of ‘Time After Time’ and ‘A Bit of a Stretch’, about how prisoners get contraband and chicken stew inside their cells.