Levin feels terrible after having been so out of place in Moscow high society—his self-confidence is at a dismal low. He thinks that he's a loathsome person who doesn't deserve anything.
He goes to visit his brother, Nicholas, the troubled man whom he talked about with Koznyshev (remember, Koznyshev is his half-brother).
Levin believes that he and Nicholas have similar souls.
For quite some time, Nicolas has lived like a monk—fasting and praying and abstaining from pleasure. Everyone, including Levin, made fun of him.
Levin believes that Nicholas isn't to blame for his bad character, because he always has good intentions—they just haven't worked out in practice.
Levin is determined to help his brother.
When Levin arrives at his brother's apartment, other people are there. Nicholas is very thin, weak, and sickly.
Nicholas addresses Levin as "Kostya" (his nickname), and demands to know why Levin has come for a visit.
Levin says there's no particular reason. Nicholas introduces Levin to Kritsky, with whom he has been friends with since they spent time together in Kiev. Nicholas also introduces Levin to Masha Nikolayevna, whom he took out of a whorehouse and insists that everyone respect as his wife.