- The chapter opens on Comrade Ossipon, who is hanging out at the apartment of the weird little maniac named The Professor. The room is shabby and gross, just like the Professors clothing and general appearance.
- The Professor is talking about a visit he recently made to Michaelis, who apparently knew nothing of Verloc's death. Apparently, Michaelis spends all his days sitting around in a nest of manuscripts, writing thought after thought without making any sense, since he has completely lost his ability to form logical connections.
- The Professor sneers at Michaelis' idealistic belief that all the strong people in future society will dedicate themselves to caring for the weak.
- The Professor thinks that the strong should devote themselves to exterminating the weak. He hates the "multitude" of mediocre people in the world, who for some reason seem to hold all the power: "First the great multitude of the weak must go, then the only relatively strong" (13.8).
- Ossipon then asks what will remain after all this exterminating, and the Professor tells him, "I remain—if I am strong enough" (13.10). Again, this is typical psychopathy coming from the Professor: the belief that everyone in the world except him is mediocre, and the belief that his poverty is just a symptom of how stupid the world is, since all the mediocre people have so much more social power than him.
- The Professor believes that he suffers from the oppression of people who aren't as great as himself: he sees the world as a bunch of leeches always trying to drain him. And yet he has no evidence at all to back up his deranged belief in his own greatness.
- Ossipon asks the Professor to come drink with him, since he seems to be pretty desperate for company. The Professor is happy about the offer for free drinks, and he starts teasing Ossipon about all the women he's been with. He even asks melodramatically if a woman has ever killed herself for Ossipon. Ossipon gets really angry at this.
- As soon as they're on a bus heading for the bar, the Professor loses his confidence while looking at the masses of people on the streets. He realizes that to regain his confidence, hell have to go sit in his room later in the day. Just as we saw in Chapter Four, the Professor has a very difficult time believing in his own greatness when he recognizes just how many people are swarming over the planet Earth, and just how many of these people have no clue who he is.
- They sit down in the bar, where Ossipon says that Michaelis might not be so far off in his judgment, since humanity wants to live, and caring for the weak might be part of this.
- The Professor insists that, "Mankind […] does not know what it wants" (13.24). Ossipon counters by saying that no matter how great the Professor thinks he is, he's still going to die someday, and the world will forget him as if he never existed.
- The Professor simply retorts that Ossipon is a "humbug" or grouch (13.28). Nonetheless, Ossipon's words have had an effect on him. "The thought of a mankind as numerous as the sands of the seashore, as indestructible, as difficult to handle, oppresse[s] him" (13.29).
- The Professor thinks of Verloc (supposedly) blowing himself up. This happened only a week earlier, and already people have stopped talking about it.
- Ossipon, without thinking, pulls a folded newspaper out of his pocket. He glances at the final lines of a story, which read: "An impenetrable mystery seems destined to hang for ever over this act of madness or despair" (13.33).
- Then he reads the headline, which mentions the "Suicide of Lady Passenger from a cross-Channel Boat" (13.35). Ossipon thinks about all the appointments he has with the various women in London who support him financially. But he can't go see any of them, because he can't stop thinking about Winnie, who is obviously the woman who has killed herself in the article. This explains why Ossipon was so rattled when the Professor asked him if a woman had ever killed herself for him.
- Ossipon thinks over the story in the paper, which speaks about a woman in black who was seen wandering around the boat from England to France as though she were very sick.
- A few crew members made her lie down on the deck while they left for five minutes. When they came back, she was gone. An hour later, "one of the steamers hands found a wedding ring left lying on the seat" (13.39). The date of her wedding was on it, which was June 24th, 1879. Knowing that she was married for seven years, we can deduce that this story has taken place in 1886.
- The Professor has gotten restless at Ossipon's silence, so he gets up to leave. Ossipon tells him to stay, and asks him if he knows anything about madness and despair. The Professor replies that there is no such thing as madness or despair in the world anymore, since these are strong emotions, and the world is governed completely by limp, flavorless emotions.
- He goes on to tell Ossipon that he (Ossipon) is mediocre, and that Verloc was mediocre, too. "Everybody is mediocre" (13.44). He also says that he's heard about the bit of money Ossipon has come into, and says that it hasn't made him any more intelligent. The Professor is obviously referring to Winnie's money, which Ossipon has been spending on booze.
- Ossipon offers the Professor all the money he has. The Professor answers by saying that he's got a shipment of chemicals coming in that he can't pay for, so he'll send Ossipon a bill.
- After the Professor leaves, Ossipon gets up to go, too. He feels completely alone in the world. He cannot face another woman ever again. "His revolutionary career, sustained by the sentiment and trustfulness of many women, [is] menaced by an impenetrable mystery" (13.54), which is the madness and despair that Winnie Verloc felt in her final moments.
- Ossipon feels that he's become mentally ill, and walks with almost no feeling in his entire body.
- Meanwhile, "the incorruptible Professor walk[s], too, averting his eyes from the odious multitude of mankind" (13.56).
- His fantasy of being a superior, talented human being can no longer sustain itself in the face of humanity's sheer numbers. It's impossible to be as important as he thinks he is, because there are simply too many people for any individual to stand out in the world.
- The final lines of the book read: "Nobody looked at him. He passed on unsuspected and deadly, like a pest in the street full of men" (13.56). In other words, the book doesn't deny that the Professor (with the bomb in his pocket) is still deadly.
- Rather, the fact that he's deadly doesn't make him superhuman. At the end of the day, he's just a little pipsqueak who's going to die like everyone else.
- The End. That's Conrad for you: good (and by "good" we mean "bleak as anything") to the last drop.