In the summer of 1918, the situation in Transcaspia was especially difficult. The Menshevik government led by Funtikov seized power. Only the fortress city of Kushka remains Soviet. The garrison went over to the Bolshevik side. Large reserves of weapons and ammunition are concentrated in the fortress, which especially attracts the Mensheviks and the British who help them. The commander of the garrison, the former tsarist general Vostrosablin, decides not to surrender the fortress. To do this, he and Commissar Morgunov are developing a defense plan. White Colonel Zykov, with the support of the Basmachi and the British, hopes to take Kushka. But the tough confrontation between the parties ends with the victory of the defenders of the fortress.