Tonight a three-person team—the prison’s designer (called 'Dad' by someone present), Dave, and Mason—launches a high-risk operation to use an internal access tunnel the designer created. He warns one wrong step will mean death. Dave will follow him into the tunnel while Mason keeps watch for guards. At the target spot the designer has them scrape rust and explains contractors used cheap scrap metal in the pipes. He mixes salt, vinegar and hydrogen peroxide and applies it; the chemicals will eat through the metal in hours. They apply the mixture and must now wait for the result.