Andrey Semyonovitch tells Raskolnikov and Sonia that Katerina is losing it.
She plans to take the children out on the street to beg. She's teaching them songs to sing and dances to dance.
Immediately Sonia grabs her coat to go to them. Raskolnikov and Andrey Semyonovitch don't go with her, but walk together.
Raskolnikov asks Andrey Semyonovitch if he's talked to Katerina about her tuberculosis.
Andrey Semyonovitch says she won't listen to anything. He talks about experimental cures for mental problems.
When they get to Raskolnikov's house, Raskolnikov leaves Andrey Semyonovitch standing there.
He doesn't know why he came back to this room. He feels completely isolated.
Guilt over burdening Sonia with his problems makes him think he could "hate her" in the future. He decides he doesn't want her involved in the mess. He thinks maybe prison is the answer.
Very soon, Dounia arrives. She apologizes for visiting (remember, he told her not to) and he sees that she loves him.
Razumihin has explained everything to her, and she knows he's being wrongly suspected of the murders.
She tells him she understands he has to handle this, that she'll protect Pulcheria and set her at ease about Raskolnikov's absence.
When she's leaving, Raskolnikov tells her he thinks Razumihin is a great guy.
This makes her blush, and then Raskolnikov says more good things about him, including a direct hint that she and Razumihin could be a good couple.
Then he says good-bye to her in a final sort of way.
Raskolnikov wants to hug her and kiss her, but he's afraid she'll be creeped out later, when she finds out he's a murderer. She'll take it badly when she knows, he thinks.
Now he's going to try to find Sonia and Katerina.
He runs into Andrey Semyonovitch, who gives him the lowdown: Katerina has the kids on the street, singing and dancing for money, while Katerina runs about frantically and violently. Sonia is trying to get her off the street.
From the bridge near Sonia's house, they can hear Katerina. She's obviously horribly ill, and is rushing around talking loudly, urging the children to perform. She wants everyone to see what's happened and feel bad about it.
As you might expect, crowds have gathered.
When somebody makes fun of them, Katerina attacks.
She has coughing fits and is crying.
Sonia is running after them, trying to reason with Katerina, but Katerina tells her to leave them alone. It's been hard enough on Sonia. Everybody can see how badly their lives have become. Even Raskolnikov tries to get her off the street.
A policeman comes, gives her some money, then tells her to get off the street. She doesn't have a license for public performance and is disturbing the peace.
Kolya and Lida, the two youngest kids, can't take the scene; they run away.
Katerina urges Sonia to go find the two children for her, then collapses, bleeding.
Sonia gets help carrying Katerina to her room. Seeing the room, Katerina apologizes to Sonia for all she's had to go through.
A crowd has gathered (of course) in Sonia's room. Raskolnikov sees Svidrigaïlov there, but can't figure out from where he's come. Katerina calls her children (all of them have been found) to her side. She's says she doesn't need a priest, because she has no sins. Very soon she dies.
Svidrigaïlov picks this moment to talk to Raskolnikov, privately. He draws him away from the crowd.
His plan is to pay for the funeral, then get the kids into good orphanages and help Sonia. He'll use the money Dounia doesn't want.
Ever suspicious, Raskolnikov wants to know why he's being so helpful. In answer, Svidrigaïlov quotes Raskolnikov's earlier conversation with Sonia (the confession), letting on he knows he's the murderer.
Raskolnikov is stunned.
Svidrigaïlov reveals that he's Sonia's neighbor, then, in a jolly way, suggests that he and Raskolnikov are going to get to know each other much better, and that Raskolnikov will see what an easygoing guy he is.