Makerenkov

 was a fellow prisoner with the First Doctor and Ian Chesterton during the Russian Civil War. He was a chimney sweep by trade and came to Ekaterinburg for work. He was worried about the Doctor being taken off by Grigory Nikulin. He later tried to escape the frontline. He told Ian that he came to the city in order to help the Romanovs to escape. He shot Thomas Preston so that he could get to the Romanovs as he was ordered to be their executioner. (AUDIO: Last of the Romanovs)