The young Étienne Lantier arrives from Lille to Montsou, seeking to be forgotten. In the mine he discovers harsh working conditions, but he decides to stay, especially for the beautiful Catherine.
The miners' anger continues to grow in the face of injustice; at the Maheu's, the grandfather can no longer work; Maheude offers for Etienne to come stay with them in exchange for rent, a decision that does not please Catherine.
To bring the workers back to work as quickly as possible, the company sends Bressan; some give up and join the Jean Bart pit; Étienne tries to keep the miners united.
Bressan contacts the gendarmerie in order to prevent other miners from striking; Deneulin pressures Chaval to get his colleagues to come back down to the mine; furious, the strikers attack the installations.
Etienne hides to escape the gendarmes and Bressan, who wants at all costs to arrest the man he thinks is the leader of the strikers. Hennebeau calls on Belgian workers to restart production. The miners are outraged and attack the newcomers, placed under the protection of the police. Elsewhere, Alzire, one of the Maheu's daughters, falls seriously ill.
After the dramatic confrontation between the gendarmes and the miners, the latter are divided. Some, believing they have nothing more to lose, are of the opinion they should go even further and kill Bressan.
