The man who enters Geiger's house is Eddie Mars. Marlowe tries to talk himself out of the situation, saying that he and Carmen are business acquaintances who stopped by Geiger's to pick up a book. Mars does not believe Marlowe. He allows Carmen to leave, but tells Marlowe he would like to talk to him a little bit longer. Mars then adds that he has two of his men outside, who would be willing to do whatever he asks them to do with Marlowe. Carmen runs for the door and leaves.
Eddie Mars claims that he senses something is wrong, and he then notices a spot of Geiger's blood on the floor. Marlowe acts as if it is the first time he has seen the blood. When Mars threatens to bring in the law, and Marlowe does not react, Mars asks Marlowe to explain who he is. Marlowe tells him his name and says that he is a sleuth. Marlowe then continues by saying that Carmen is a client whom Geiger had involved in blackmail—they had come to the house in an attempt to solve the problem. The door had been open. When Marlowe asks how Mars got a key to Geiger's house, Mars says that he owns the house Geiger lives in, and that Geiger is therefore his tenant.
Geiger and Marlowe embark on what is one of the many quick, "hard-boiled" conversations in the novel. Mars acts as if he simply wants to know what has happened to Geiger, as Geiger has been missing from the store and nobody knows where he is. Marlowe tells Mars that he knows who Mars is, and that he knows Mars probably provides the kind of "protection" that someone like Geiger needs in the pornography business. Marlowe also adds that someone is trying to move in on the business because he thinks Geiger is dead. Marlowe continuously plays on Mars, revealing only what he wants, when he wants, in order to gauge Mars's reactions.
Eventually, Marlowe annoys Mars, prompting Mars to call for his "boys," his gunmen, with a whistle. The two gunmen enter and, upon Mars's request, they frisk Marlowe for weapons. They find that he is unarmed, that his name is in fact Marlowe, and that he also does in fact have a detective license. In the end, Marlowe does not give any of the information he holds about Joe Brody, Carmen, or anything else. Eventually, Mars lets Marlowe go. Marlowe goes back to Hollywood.
Marlowe goes back to Joe Brody's apartment building. He knocks on the door. Marlowe eventually makes his way inside by telling Brody that he knows Brody has Geiger's books. Marlowe says that he has the list of customers and that Brody should, therefore, talk. Brody has a gun, and points it at Marlowe. Agnes Lozelle, the blond from Geiger's shop, is also in the room. Agnes initially denies Marlowe's accusations about the kind of "smut" business Geiger was running out of the bookshop.
Marlowe explains, however, that it may seem to others that Brody had every reason to have committed the murder—even if he did not—in order to take over the porn racket that Geiger owned and that Brody now has in his possession. Marlowe also says that he knows Brody has the pictures, that he sent the blackmail letter to Vivian, and that Agnes was the female voice that delivered the telephone message to Vivian. Brody, as he starts to give in to Marlowe's pressure, relinquishes another clue. He asks if the "witness" Marlowe mentions regarding Geiger's murder was the "punk kid" that worked at the store who disappeared after the truck left. This young man is a new character whom we later learn to be Carol Lundgren, Geiger's homosexual lover.
After a long talk, Marlowe realizes that Brody is telling the truth about not having been in the house and not having been part of Geiger's murder. Brody explains that Carmen hates him because he broke up with her for being too crazy for him. Being rejected, it seems, is not something that Carmen likes. Marlowe finally convinces Brody to hand over the pictures, but just as he is about to reach for them, the doorbell rings.
Before he reaches for the door, Brody hands a gun to Agnes so that she can keep it pointed at Marlowe. Brody also has a gun of his own. At the door is Carmen Sternwood, also with a gun in hand. Carmen has come to take her pictures back. She claims that she saw Brody kill Arthur Geiger, which is untrue, but which works as a framing device and as a reverse piece of blackmail to accompany her gun. While Brody answers the door and Carmen catches him off guard, Marlowe grabs the gun from Agnes.
A scuffle ensues. Agnes tries to get possession of her gun, but Marlowe hits her on the head. A shot goes off between Carmen and Brody, and Marlowe ultimately ends up with all the guns in his possession. Marlowe then forces Brody to hand over all the prints and negatives. Marlowe sends Carmen home, ignoring her constant flirtation, as usual, and refuses to hand over her pictures at the moment.
It is in these chapters that the hero and the anti-hero meet, the knight and the dragon, the protagonist and the antagonist—Marlowe and Mars. Mars appears composed and hard; Marlowe says he looks "hard, not the hardness of a tough guy. More like the hardness of a well-weathered horseman. But he was no horseman." Marlowe is capable of lying to Mars in order to protect what he knows and to continue to search out the truth. Marlowe does not trust anyone and is hardly ever fooled; he can clearly see that Mars is suspicious. In this scene, however, the hero of The Big Sleep does not appear to overtly win any kind of battle. In fact, it may seem as though he is a bit overpowered: Marlowe is not able to leave the scene in Geiger's house until Eddie Mars "allows" him to, for fear of his own safety. Furthermore, Marlowe is unarmed. In his search for the truth, Marlowe has a formidable opponent.
We glimpse the unfolding of several more characters throughout these chapters. For instance, we come to the conclusion that Mars does not taint his own hands with blood, but rather has gunmen do his dirty work. We also come to conclusions about Carmen Sternwood, who, entering Brody's apartment with a gun, suddenly appears crueler and more dangerous in her madness than ever before. Another thing we learn about Carmen is that she does not like to be rejected. As the story unfolds, this trait becomes a motive for barbarous acts. Marlowe, as usual, keeps his cool and prevails, even managing the near-superhuman feat of obtaining all the threatening guns at once.
Chandler juxtaposes different types of criminals in this section. Carmen, for instance, appears to be capable of committing crimes without fully thinking about them; she is willing to kill Brody, for example, simply because he has her pictures. Brody and Agnes are seemingly caught in a world of crime in which they hardly belong. These two are archetypes of the kind of inept criminal who is trying to make an easy buck, believing there is no other way out. Brody and Agnes are not as intelligent, as cruel, or as dangerous as Eddie Mars. The fact that everyone in the novel is involved of some kind of criminal activity—even Marlowe, who has committed a crime by not relaying what he knows to the police—we are fully immersed in the various shades of the seedy side of Los Angeles Chandler is trying to portray.