Some nine months after the Dostoevskys' departure from Geneva, a twenty-one-year-old Russian radical named Sergei Nechaev arrived in the city. He was of medium height and weight and possessed an abundance of nervous energy. To some his compressed lips and the look in his dark eyes hinted at the sinister nature of the man. Unlike Ogarev and Bakunin, both of whom he would soon meet, he was not from the noble class. His father worked as both a waiter and a painter of signs in and around Ivanovo, a small Russian textile town. Already hostile to the local nobility, he left his hometown in 1865 and went to Moscow. There he briefly worked as a copyist for the historian Pogodin before moving on to the capital, where he obtained a teaching position.

For almost three years St Petersburg was his home. He witnessed the reaction symbolized by Muraviev's investigating commission and the appointment of several new men to key posts. One of these was the new Minister of Education, Dmitry Tolstoy, who in the year following his appointment issued new rules further restricting students' rights. Partly in reaction to these further restrictions, students, who had quieted down a bit during the middle of the decade, once again became more active in 1868 and 1869. The number of illegal circles and meetings increased significantly, and Nechaev, who enrolled as an auditing student at St Petersburg University, became active in the midst of them.