Cholera returns to Dhaka every year, spreading fastest through neighborhoods where clean water is scarce and sanitation is worse. Filmmakers Orlando de Guzman and Andrew Marshall follow one hospital in the city that has shifted from treating outbreaks after they happen to trying to stop them before they start, a preventative approach doctors there believe could serve as a model for cholera-prone cities elsewhere. The film shows what that work looks like on the ground: patients arriving dehydrated and in danger within hours, medical staff running rehydration wards at capacity, and health workers going into surrounding communities to push sanitation and clean-water education as the actual front line against the disease. Water itself is treated as the film's central contradiction, plentiful across the city yet mostly unsafe to drink, which is what keeps the hospital's caseload full. Part of Al Jazeera's Witness strand, the film stays close to patients and staff rather than officials, tracking a public health problem that is, at its core, a plumbing and sanitation problem.