In the wee hours of the night, two lamplighters and their apprentice ride through Belfast, replacing old sodium-vapor streetlights with LEDs. Sodium lights have been in use across the globe to light municipal streets with their warm amber glow since the 1930s, when they replaced the gas lights of the 19th century. In a world increasingly obsessed with efficiencies and cost savings, LED lighting has quickly become the norm due to its lower energy usage and longer lifespan, despite harsh blue-light emissions that negatively impact both nocturnal animals and human health. Using a vérité style and long static shots, No Mean City straddles the ambiguity of LED lighting’s environmental and human impacts, showcasing a city ushering in a new dawn of technological advances even as its workforce faces growing obsolescence. BD