As you probably guessed, the letter causes Raskolnikov pain.
He knows one thing for sure: Dounia and Luzhin will get married over his dead body, and Pyotr Petrovitch Luzhin can "be damned."
(Now we get to "hear" Raskolnikov talk to himself about his mother's letter.)
We'll go over the main points:
His mother and sister thought they could do this whole thing behind his back, and make it too late for him to stop it.
He can't believe this business about Luzhin pressuring them to decide quickly because he was so busy.
Now Raskolnikov starts addressing his sister, saying he knows what she was praying for all night before she decided. (This is clarified a bit later in this chapter.)
He says he knows exactly what she was thinking about, and praying for when she was on her knees in front of the icon "the Holy Mother of Kazan" (a famous Russian icon, believed to grant miracles) that was in their mother's room.
You might have been puzzled by this statement: "Bitter is the ascent to Golgotha."
Golgotha is the place where Jesus was crucified. Raskolnikov is accusing his sister of being martyr.
He stops talking to his sister and simmers for a bit about how shifty Luzhin sounds, and then he asks the question many brothers would ask: has this old guy had sex with his young sister?
He accuses his mother of basically selling Dounia to Luzhin to benefit Raskolnikov.
Distaste builds up in him over the whole affair, and he could kill Luzhin.
Now he gets on the subject of the luggage. It speaks horribly of Luzhin that he's not doing more than paying for their things to be sent to St. Petersburg. He has to be aware that Raskolnikov's mother is funding the journey by borrowing on her pension.
Then he ponders his mother's comment about not living with the married couple (as would have been the custom, since she is a widow).
He decides that Luzhin must have somehow made it clear that he didn't want her there.
What will she live on? How will she afford to live alone?
Her pension (what's left of it after all the borrowing) and money from knitting won't cut it.
She's banking on Luzhin's support.
Raskolnikov begins addressing his sister again.
She was nineteen the last time he saw her, and he knows she hasn't changed, can't have changed.
Raskolnikov ponders his sister.
She would never sell herself to a man like Luzhin, or any man. She would sooner be a slave, sooner work for the Svidrigaïlovs.
For a more comfortable life she would never "sell her soul" like this.
She has to be doing it for someone else.
She's doing it for me, Rodion Romanovitch Raskolnikov! he thinks.
The daughter is being sold to save the "precious" first-born son, he thinks, disgustedly.
Continuing his imaginary argument with his sister, Raskolnikov says that's also what's happening to Sonia Marmeladov.
Thinking of Sonia, he gets really angry, screaming (not necessarily out loud) at his sister and mother.
He will not accept this deed from his sister! He will not let it happen! No!
Then he realizes that he is powerless. It's all a question of money right now, and he has none. He's ripping them off, too. His mother's letter made that clear.
Raskolnikov berates himself, asks himself how much time he needs to be in a position to support his mother and sister.
Ten years? How far would his mother and sister fall in ten years?
Action is necessary, he thinks. Something must be done, and now. Or – I'll die! Raskolnikov decides.
His mind flies back to the mysterious terrible act he's been thinking of doing for the past month.
A spasm runs through his body, not because the idea had returned – he knew that would happen – but because it had changed into something much more real than before.
He needs to sit down. As he finds a bench, he notices a girl, walking funny, wearing a dress that looks recently torn.
When she snags the bench Raskolnikov had his eye on and collapses on it, he notices she's drunk. Since she's only about sixteen, Raskolnikov can't believe this.
As Raskolnikov stands near her, he realizes there's a dressed-up older man following her, and now looks like he's waiting for a chance to prey on her.
Raskolnikov goes up to him and calls him a Svidrigaïlov, and tells him to beat it.
They argue, and a cop comes.
Raskolnikov explains that the girl has obviously had a bad time – someone tore her dress and got her drunk, and now this guy wants to take advantage of her.
The policeman agrees with his assessment. Raskolnikov gives the cop money for a cab to take the girl home.
She's in a drunken stupor, and they try to rouse her to get the address, but she's too drunk and shoos them away.
Raskolnikov says they have to protect her from the man. The cop agrees.
The girl wakes up and walks off. The man goes after her. The cop starts to follow.
Raskolnikov gets disgusted and tells the cop to forget it, to let the man have her.
The cop thinks Raskolnikov must be insane, and goes off after them anyway, taking Raskolnikov's money, for the cab, with him. Raskolnikov is ashamed of giving away the money when his sister and mother in their current financial position.
He feels sorry for the girl, and imagines a sad and painful life for her.
Suddenly, Raskolnikov realizes he's on his way to see Razumihin, his friend from college.
Raskolnikov, as we've seen, has some social issues, and didn't have many friends at school.
Razumihin was the exception. They aren't exactly friends (Raskolnikov doesn't quite understand that concept), but Raskolnikov at least talks to him from time to time.
Razumihin is very tall and thin. He's a drinker, a brawler, and a prankster.
He's super-poor but never lets anything stand in his way and never complains of hardship.
Raskolnikov crossed the street to keep from running into him just a few weeks ago.