In the trial against Boris, Lazar is the main witness for the prosecution. The two are the comrades-in-arms. Now they are opponents, because of a conflict concerning a coal conveyor where they work. Lazar is afraid of taking risks. Boris, however, is not afraid of taking responsibility where innovation is at stake. The conflict ceases to be confined to production problems and grows into dispute over commitment to principle and ethics. After harrowing hesitations the main witness Lazar gives evidence in Boris's defense.