After the civil war in Russia, the white guard officer Aleksey emigrates to Bulgaria. He earns his living as a boatman. Nataliya Noykova, the wife of a mining engineer, is on holiday in the town. She and her friends hire Aleksey's boat. He falls for Nataliya and follows her. Aleksey works as a miner under the supervision of a man nicknamed The Hunchback. He fancies Rositza, granddaughter of the engine-driver Old Ivan, and makes rude passes at her. Aleksey rushes to her help. The two men fight... The workers are enjoying themselves at the festival of the colliery. Nataliya and Aleksey arrange for their next date. The Hunchback spies them. He blackmails Nataliya threatening reveal her secret to her husband if she does not agree to go to bed with him. Disgusted at his proposal she hits him. Nataliya send a letter to Aleksey through Rositza. The girl goes down to the pit and hands it to him. The Hunchback comes. Aleksey decides to kill him. He chases him through the galleries: the fleeing supervisor trips over some explosives, which go off. The Hunchback dies while Aleksey is badly injured. In a hospital, Aleksey is delirious: he reviews "the fire over Russia"...