In one weekend in July 2015 - by all accounts, a perfectly unremarkable one - 87 people across the US were killed in incidences of gun violence, with a further 197 injured. Methodically, this documentary sets about revisiting some of those incidents. Some are gang related. Some are arguments that escalated beyond all measure. Some stem from mental illness, other from police ineptitude. Some are simple, tragic accidents. They happen in Los Angeles, in Arizona, in South Dakota. They are disparate and unrelated, save for the type of weapon responsible for each death. The calm, patient way that the documentary unfolds suggests a systemic problem at the heart of America. It suggests an epidemic.