David Ker travels to Central Asia where he meets Captain Ostap Danilevitch Kostarenko. The Russian officer then tells him his story, of a time before the Russians came and the land was ruled by Muslim potentates. At that time raids by Muslim armies on Russian territories often resulted in the Russian population being killed or enslaved. One of those Russians who was made a slave was the young Ostap, the Boy Slave of Bokhara.