3 ideas
Pyotr Verkhovensky convinces a small provincial group of five that they are one cell in a vast national network. He then has them murder Shatov, a former member who is supposedly about to inform. Shared guilt for the killing is meant to bind them to him, but the cell collapses almost at once: Pyotr flees abroad, and the others confess or are arrested. The episode was based on the real 1869 killing of the student Ivanov by Sergei Nechaev's group.
The theorist Shigalyov admits that his system starts from unlimited freedom and arrives at unlimited despotism. In his scheme one-tenth rule absolutely and the other nine-tenths are reduced to herd-like equality. The novel argues that utopian projects which reject every moral limit do not fail by accident. Their own logic produces tyranny, because nothing remains to restrain whoever claims to speak for the plan.
Stavrogin himself taught Shatov his Orthodox messianism and Kirillov his idea of the man-god, and Pyotr wants him as the figurehead 'Ivan the Tsarevich.' Yet Stavrogin no longer believes anything strongly, so his followers remain devoted to ideas he planted and has since abandoned. Their investment in him ends in ruin, and the suppressed confession chapter reveals his abuse of a girl who then hangs herself.