At the beginning of the novel Marlowe receives his commission from his client, General Sternwood, in a hot greenhouse—a humid, jungle-like greenhouse filled with orchids and their damp, pervasive smell. The greenhouse is a symbol that represents the whole of the novel: it is a small-scale version of the rain- ridden Los Angeles and its many thieves cloying around the General and Marlowe like the vines in a jungle.
The orchids in the greenhouse thrive in the uncomfortably intense heat, and, though they seem beautiful, they release a strange odor and their petals feel like human flesh. This disquieting image opens the novel and remains in our heads throughout, following us through the jungle of Los Angeles and running across its two-faced criminals. The sensual appeal of both the city—its luxury, its casinos, its alcohol, and so on—crumbles into seediness. The sensual appeal of women, too, peals away like the petals of the orchids and gives way to something nastier.
The stained glass that appears at the beginning of the novel places Marlowe in the position of the knight. The piece illustrates a knight reaching for a woman, trying to set her free. Importantly, Marlowe finds himself staring at the glass and feeling the need to help. This is not only a symbol, but also a note of foreshadowing: Marlowe will have to rescue his own lady, in the person of Carmen Sternwood.
Another significant symbol of knighthood appears the second time Carmen needs to be rescued, when she appears in Marlowe's bed, undressed. It is here that Marlowe looks down at the chessboard in his room and, significantly, moves the knight piece. However, within the same scene, he realizes that it was the wrong move, and he retracts it, claiming that knights have no place in such a world: "Knights had no meaning in this game. It wasn't a game for knights." This admission does not necessarily mean Marlowe has lost; it simply means he is misplaced, and does not belong in such a world. He does not sleep with Carmen, he takes her home, remains chaste, and upholds his knighthood—even if the world does not recognize it, and even if it means that he will lose the game as a whole. In the end Marlowe is not any happier—perhaps he has lost in some ways. Nevertheless, he has lost only because he remains a "knight."