Prague in the 1870s. Work in Smolík's sulphur factory is hard and dangerous to health. The poorly paid workers resemble torches because their clothes are soaked with poisonous phosphorus. Young Josef Rezler also works in the sulphur factory and uses his earnings to feed his mother and little sisters. He throws his perpetually drunken father out of the house. The older worker Brož forces Josef to learn to read and write. A cholera epidemic breaks out in Prague and Josef is the only one of his family to survive the disease...