A ground beef patty on a grill looks like the simplest food there is, but Frontline traces it back through a supply chain that grinds meat from dozens or hundreds of different cattle into a single batch. The film investigates how that mixing turns an isolated case of E. coli contamination into a nationwide recall, following outbreaks that sickened children and interviews with parents whose kids nearly died from tainted burgers. USDA officials and meatpacking executives explain the inspection system and its limits, while food safety advocates argue the checks are too weak to catch contamination before it reaches supermarket shelves. The reporting moves from feedlots to processing plants to congressional hearings, laying out why regulators have been slow to require more aggressive testing even after well-documented outbreaks. It is a plain, fact-driven account of how industrial scale changed a basic food, and why that change made a hamburger a genuine food safety risk rather than a simple meal.