1. "All descriptions of artwork, architecture, documents, and secret rituals in this novel are accurate" (Fact). This flat statement gives The Da Vinci Code more power and influence than most works of fiction.

2. "If I die, the truth will be lost forever," and "I must pass on the secret" (Prologue). Jacques Saunière thinks this as he is dying. The truth and secret referred to is the secret meaning of the Holy Grail.

3. Collet shows Langdon a picture of Saunière dead, in an odd position, and says, "Monsieur Saunière did that to himself," meaning that Saunière positioned himself in a meaningful fashion—one that would send a message—even as he was dying (Chapter 1).

4. Langdon is driven to the Louvre to meet Captain Bezu Fache, nicknamed le Taureau (the Bull). As Langdon waits for Fache, he thinks, "I'm trapped in a Salvador Dali painting," because the situation seems so symbolic and surreal (Chapter 3). It also indicates Langdon's tendency to interpret the physical world through art.

5. Fache takes Langdon to Saunière's body, making him crawl under a steel grate to access it. Langdon thinks, "The barricade looked like a guillotine waiting to crush intruders," but it is actually a symbolic barrier, marking Langdon's passage into a new, mythic realm (Chapter 4).

6. Fache shows Langdon Saunière's body, and they discuss the symbols around it, which include a pentacle drawn on his body. At one point Langdon thinks, "So much for the goddess of love and beauty," summing up the ways that the symbols of the feminine have been demonized (Chapter 6).

7. Langdon is shown the message which Saunière wrote while dying:

13-3-2-21-1-1-8-5
O, Draconian devil!
Oh, lame saint!" (Chapter 8)

Langdon recognizes the circle Saunière drew around his body and the posture in which Sauniere's body is arranged as matching that of Da Vinci's The Vitruvian Man He begins to decipher Saunière's code in those terms, giving the first extended suggestions that Da Vinci and others view the Catholic Church's influence negatively (because "Draconian" means very harsh, after the Greek politician Draco, and because the term "lame saint" suggests the church is not as "fit" as it thinks).

8. When Langdon calls the number that Sophie tells him belongs to the U.S. Embassy, he hears Sophie's voice: "'Mr. Langdon,' the message began in a fearful whisper, 'Do not react to this message. Just listen calmly. You are in danger right now. Follow my directions very closely'" (Chapter 9). From this point on, Sophie guides Langdon out of danger and into a Grail quest. Also, reading his message symbolically, Sophie might be considered Langdon's "embassy" from this point on: his sacred ground to protect.

9. At the crime scene in the Louvre, Sophie puts numbers in order from smallest to largest (1-1-2-3-5-8-13-21), and calls the new order a Fibonacci sequence. This is "a progression in which each term is equal to the sum of the two preceding terms" (Chapter 11). For example, 1 + 1 = 2, 1 + 2 = 3, 2 + 3 = 5, and so on.

10. Sophie meets Langdon in the restroom, where she tells him that he is being tracked with a surveillance bug and that Fache thinks Langdon killed Saunière, largely because there was a fourth line in the message Saunière wrote: "P.S. Find Robert Langdon" (Chapter 12).

11. Sophie recalls her painful memories of her grandfather and their shared past. She mentally replays her grandfather's final phone message left that afternoon, including the haunting line, "'Please, I must tell you the truth about your family'" (Chapter 16). Sophie replays this line repeatedly, treating it like the puzzle to her family, and her identity: does it refer to her lineage, how her parents died, or to her grandfather's secret actions? In the end, it is all of these.

12. "'PHI's ubiquity in nature … clearly exceeds coincidence, and so the ancients assumed the number PHI must have been preordained by the Creator of the universe. Early scientists heralded one-point-six-one-eight as the Divine Proportion'" (Chapter 20). Here Langdon displays his knowledge of ancient wisdom, a scholarship that allows him to see the meaning coded into the entire world.

13. Langdon remembers lecturing on the anatomical proportions of figures in art. This gives him the clue to the code. The letters in "O, Draconian devil! / Oh, lame saint!" are an anagram of Leonardo da Vinci and the Mona Lisa (Chapter 20).

14. "'Princess,' he smiled. 'Life is filled with secrets. You can't learn them all at once'" (Chapter 21). As she is thinking about her first encounter with the Mona Lisa, Sophie remembers this statement which her grandfather made at the time. The line shows the affection between the two of them, uses her nickname, and, most importantly, indicates that Saunière is aware of the need for one's understanding to grow at the proper pace, an understanding which guides the entire novel.

15. Langdon and Sophie read the message on the Mona Lisa: "So Dark the Con of Man," which Langdon interprets as meaning early Christians devaluing the feminine a "con" or deception—a belief of the Priory of Sion that perpetuates their goddess worship. (Chapter 28).

16. "What kind of God would want a body punished this way?" (Chapter 29). Sister Sandrine thinks this when she sees Silas's bloody body. This thought sums up the reactions of the good characters when they encounter violence: they are sickened and do not see the world this way.

17. In the Church of Saint-Sulpice, Silas breaks the stones open, finding a reference to the Bible verse Job 38:11, "Hitherto shalt thou come, but no further," which is meant to signify the fact that this is a dead end: a false keystone (Chapter 29).

18. Once she and Langdon are past Grouard, Sophie explains that "so dark the con of man" is another anagram, this one for "Madonna of the Rocks," the Da Vinci painting that Sophie is holding hostage (Chapter 30).

19. "I WAS THERE. DON'T TRY TO FIND ME." This is the note Sophie leaves to sever contact with her grandfather after she accidentally sees him engaged in a sexual ritual (Chapter 32).

20. "'Sophie, the word Sangreal is an ancient word. It has evolved over the years into another term … a more modern name.' He paused. 'When I tell you its modern name, you'll realize you already know a lot about it. In fact, almost everyone on earth has heard the story of the Sangreal'" (Chapter 37). This is Langdon's introduction to his explanation of the Holy Grail. It is important because it sums up Dan Brown's approach to knowledge; the novel asks its readers to recast things they already know, but in a different form.

21. "A proof of merit. She could feel her grandfather's hand at work. The keystone is a map that can be followed only by the worthy." (Chapter 51) Sophie thinks and feels these things as she's trying to decipher the cryptex. They mark the morally encoded nature of the universe, and show her grandfather's influence.

22. "Langdon gave an awkward smile. 'We're on a Grail quest, Sophie. Who better to help us than a knight?' "(Chapter 51) Langdon's awkwardness and his joking tone show he is both humble and modern in the face of a quest (he doesn't assume he's worthy, or that quests are understood), but also signal that this is a quest, and one on which they need help.

23. "'Indeed I will open the gate,' Teabing proclaimed, 'but first I must confirm your heart is true. A test of your honor. You will answer three questions.'" (Chapter 52) This shows the difference between Teabing and Langdon. Langdon is unsure about deserving to be on a quest even when he consciously is on one; Teabing seizes the right to judge even when joking.

24. As Teabing explains the meaning of the Holy Grail to Sophie, he points out lines from. Da Vinci's journals:

"Many have made a trade of delusions and false miracles, deceiving the stupid multitude." "Blinding ignorance does mislead us. O! Wretched mortals, open your eyes!"

Teabing argues that these lines indicate Da Vinci and others objected to the lies in the Bible. Teabing then retells the history of the Church as a history of deception (telling outright lies) and conversion of pre-existing religious practices and symbols for its own purposes. He then walks Sophie through a viewing of Da Vinci's The Last Supper, pointing out that the Holy Grail can't be the cup Jesus and the disciples shared there because there were many cups at the table. Instead, "The Holy Grail is not a thing. It is, in fact …a person." (Chapter 55)

25. The chapter ends with Teabing guiding Langdon and Sophie to see Da Vinci's painting of the woman who is the Holy Grail, "A woman who carried with her a secret so powerful that, if revealed, it threatened to devastate the very foundation of Christianity!" (Chapter 56)

26. Teabing explains The Last Supper to Sophie, arguing that the figure seated to the right of Jesus, "at the place of honor," is Mary Magdalene. Teabing claims that "The Church needed to defame Mary Magdalene in order to cover up her dangerous secret—her role as the Holy Grail." He says that she was not a prostitute, but rather Jesus's wife, and that "Not only was Jesus Christ married, but He was a father." The chapter ends with Teabing arguing that the name of the Holy Grail—Sangreal—actually means "Sang Real." Sophie realizes that "Sang Real literally meant Royal Blood," which convinces her that the Grail really does mean the blood of Christ: his family lineage. (Chapter 58)

27. Flying over the Tyrrhenian Sea, Bishop Aringarosa thinks "Everything in Paris has gone terribly wrong." This refers to Langdon and Sophie getting away with the keystone, and indicates that he has some way of knowing this. (Chapter 63)

28. They flee France in Teabing's plane. As they discuss whether or not to make the Grail documents public, Sophie quotes Teabing's words back to him, " 'You do not find the Grail, the Grail finds you.'" and continues, saying, "I am going to trust that the Grail has found me for a reason, and when the time comes, I will know what to do." Here Sophie comes into her own, morally. (Chapter 69)

29. The inscription is English—and poetry-- but ciphered. It reads: "An ancient word of wisdom frees this scroll…and helps us keep her scatter'd family whole…a headstone praised by templars is the key…and atbash will reveal the truth to thee." Langdon explains that "The Atbash Cipher is one of the oldest codes known to man," a Hebrew encoding system based on letter substitution. (Chapter 72)

30. Alone again, Langdon and Sophie discuss the rift between Sophie and her father. Langdon speculates accurately that Sophie had stumbled into a sex ritual involving her grandfather, the Hieros Gamos, saying "Historically, intercourse was the act through which male and female experienced God. The ancients believed that the male was spiritually incomplete until he had carnal knowledge of the sacred feminine." Sophie tumbles back into her memories, and how disturbed she was by what she'd seen: her masked grandfather (who she recognized via a birthmark on his shoulder) making love to a masked woman, while a crowd of masked and robed figures chanted. (Chapter 74)

31. They work together with the Atbash cipher to figure out how to spell Baphomet in Hebrew, then convert Sophie's name to "S-O-F-I-A" because "Sophia literally means wisdom in Greek. The root of your name, Sophie, is literally a 'word of wisdom.'" This code both shows how much Sophie's grandfather loved her, and how much her identity is shaped by the past. (Chapter 77)

32. Inside the cryptex there is a second, smaller cryptex inside, this one black to the first's white. Another four line poem of clues is inside, the first line of which reads, "In London Lies a Knight a Pope Interred." (Chapter 78)Within every answered riddle is another riddle.

33. As they drive through London, Langdon reviews the entire four line poem:

"In London lies a knight a Pope interred. His labor's fruit a Holy wrath incurred. You seek the orb that ought to be on his tomb. It speaks of Rosy flesh and seeded womb."

They all speculate on what this might mean, and Teabing suggests they visit the Temple church, which has, he explains, pagan architecture: a round design, to honor the sun. Remy doesn't know exactly how to get there, so Teabing goes forward to guide him, leaving Langdon and Sophie mostly alone. They again discuss what to do with the documents, once accessed, and the implications of literal faith. (Chapter 82)

34. Langdon and Sophie got to King's College to consult the database in the Department of Theology and Religious Studies, for help breaking the code in the verse. The librarian recognizes Langdon, and even says, "I can only assume that you are on a Grail quest" due to his fame in religious studies and the centrality of that library for Grail seekers. However, this casual comment also names the essential nature of their search: Sophie and Langdon are on a quest for the Grail. (Chapter 92)

35. The Teacher meets Remy in St. James's Park in London. Remy expects to be rewarded for his actions, but instead is poisoned because he's seen the Teacher's face and could identify him. After this, the Teacher heads for the site of the knight where he'll find "seek the orb that out to be on his tomb." (Chapter 94)

36. Langdon and Sophie find the note at Newton's tomb, which reads "I have Teabing. Go through Chapter House, out south exit, to public gardens." (Chapter 98) They do, only to have the door shut behind them by Leigh Teabing, who is pointing a gun at them. While Teabing meant the note to manipulate, writing it in the third person also symbolizes how his passion for the grail possesses him.

37. In the Chapter House, Langdon weighs his choices. As Teabing watches, he remembers luring Silas to his death by having Silas tell him he'd received information about S's family's death. Langdon tries to trick Teabing by lying to him, then does trick him by throwing the cryptex into the air after having set the dials to spell out the missing five letter word: apple. This was the "orb" missing from Newton's tomb; the "Rosy flesh and seeded womb" of the verse refers both to the apple's color and seeds, and to the eternal feminine, which is symbolized by the rose. (Chapter 101)

38.

"The Holy Grail 'neath ancient Roslin waits. The blade and chalice guarding o'er her gates. Adorned in masters' loving art, She lies. She rests at last beneath the starry skies."

Sophie's grandmother Marie counsels Langdon to be patient and he'll eventually figure out where the Grail is. (Chapter 105)

39. Like the first chapter, the epilogue opens with Robert Langdon waking up, disoriented, in a hotel room in Paris. However, this time he is awakened by intuition. He follows it to "The earth's original prime meridian. The first zero longitude of the world. Paris's ancient Rose Line." He follows his intuition to La Pyramide Inversee at the Louvre, where he realizes the physical Grail is now housed. (Epilogue.)

40. "For a moment, he heard a woman's voice…the wisdom of the ages…whispering up from the chasms of the earth." (Epilogue.) These are the last lines in the novel, and Robert Langdon's final thoughts on the entire adventure—and they sum it up. There is a moment, a brief time, when the worthy can open to the hidden wisdom of the divine feminine in the world of The Da Vinci Code. If they hear those whispers, they reach wisdom (Sophie), and the Grail.