Chapter 41
Chapter Characters:
Bishop Aringarosa
Vatican officials

Chapter Summary:
At Castel Gandolfo, Bishop Aringarosa enters the library, where he finds the Secretariat Vaticana and two Italian cardinals. They give Aringarosa a briefcase containing Vatican bearer bonds worth twenty million euros. Although they would have preferred giving cash to Aringarosa because the bonds are traceable to the Vatican Bank, Aringarosa remembers the Teacher suggesting bonds as insurance: "We are all in this together now."

Aringarosa then heads for Paris.

Chapter Themes:
The power of belief, and the need to believe.

Chapter 42
Chapter Characters:
Robert Langdon
Sophie Neveu
Bezu Fache
JéromeCollet

Chapter Summary:
At the Depository Bank of Zurich, Sophie and Langdon repeatedly use the key to pass through barriers. When they enter the bank, a guard guides them to the elevator to their floor. Having seen their pictures being circulated by the French police on television, the guard reports to the bank manager that two fugitives are in the bank, and then he calls Interpol.

When they get to the lavish room awaiting them, a banker explains how the boxes work: they need an account number to go with the key (which Langdon and Sophie do not have at present). The banker receives a call and leaves the room, locking them inside.

Across town, Fache calls Collet to tell him that Interpol was tipped off and that Langdon and Sophie are at the bank.

Chapter Themes:
The human world is encoded with meaning.

Chapter 43
Chapter Characters:
Robert Langdon
Sophie Neveu
André Vernet

Chapter Summary:
André Vernet (president of the Paris branch of Depository Bank of Zurich) was awakened by a subordinate, who told him of the fugitives. Wanting a gold-key client who is also a fugitive out of his bank as soon as possible, he hurries to Sophie and Langdon. Recognizing Sophie, he seems surprised, more so when he learns Saunière is dead. He tells them that Saunière was a dear friend but that he does not have the secret code to the vault. Sophie shows Vernet the Priory of Sion seal on the key her grandfather had left her. She said her grandfather wanted to give her something and wonders if the contents of his safe-deposit box have anything to do with the Sangreal. Vernet says he knows nothing.

A phone call lets Vernet know that the police are there. Not wanting an arrest to be made at his bank, Vernet leaves the room to arrange Sophie and Langdon's escape. Soon thereafter, Langdon realizes they already have the code, from the first line of Saunière's last message: "13-3-2-21-1-1-8-5."

Chapter Themes:
The human world is encoded with meaning.
The influence of the past upon the present.

Chapter 44
Chapter Characters:
Robert Langdon
Sophie Neveu

Chapter Summary:
Langdon types in the ten digits, but Sophie decides they need to reorder them into the Fibonacci sequence, "1-1-2-3-5-8-13-21." They enter the reordered numbers, and a robotic claw moves through the vault, eventually bringing them a crate with a polished wooden box in it.

The rosewood box has an inlaid five-petal rose on it, which Langdon explains is a Priory symbol for the Holy Grail. They open the lid and realize the object inside is not the Cup of Christ.

Chapter Themes:
The human world is encoded with meaning.
The influence of the past upon the presen.

Chapter 45
Chapter Characters:
Robert Langdon
Sophie Neveu
André Vernet
JéromeCollet

Chapter Summary:
Vernet enters, letting them know the police have blocked the street. Vernet is surprised to see that they had accessed Saunière's account and wants them out of the bank. He guides them into an armored car, and poses as the driver to get them through Collet's blockade.

Chapter Themes:
The human world is encoded with meaning.
The centrality of human relationships, especially male-female relationships.

Chapter 46
Chapter Characters:
Silas, the albino monk
The Teacher

Chapter Summary:
Alone in his room, Silas is weak from self-flagellation and despair. He remembers learning from Aringarosa five months earlier that something terrible would happen in six months. He calls the Teacher to tell them all is lost, but the Teacher tells him that Sauniere transferred information, and so there is still hope.

Chapter Themes:
The power of belief, and the need to believe.
The influence of the past upon the presen.

Chapter 47
Chapter Characters:
Robert Langdon
Sophie Neveu

Chapter Summary:
In the armored car, Sophie and Langdon open the box. Inside they find a cryptex, an encoded cylinder with different disks that can be turned to spell out key phrases, modeled on Da Vinci's designs. The cryptex contains a simple booby trap, so that if one attempts to open it without the correct code, one destroys the message inside. As Sophie explains the cryptex and Langdon the historical symbolism of the rose, Langdon realizes what it is.

Chapter Themes:
The human world is encoded with meaning.
The centrality of human relationships, especially male-female relationships.
The influence of the past upon the present.

Chapter 48
Chapter Characters:
Robert Langdon
Sophie Neveu
Andre Vernet

Chapter Summary:
Langdon realizes he's holding the Priory's keystone. As he explains why he thinks so, he also explains the Priory's policy of having four top members who all knew where the Grail was, but with the knowledge transmitted only orally (never written down). After Langdon's explanation, Sophie suggests that her grandfather was the Grand Master. Their suppositions are interrupted when Vernet stops the truck and draws a gun on them.

Chapter Themes:
The human world is encoded with meaning.
The centrality of human relationships, especially male-female relationships.
The influence of the past upon the present.

Chapter 49
Chapter Characters:
Robert Langdon
Sophie Neveu
Andre Vernet

Chapter Summary:
Vernet explains that he's doing this because of the four murders—Sauniere and three others—which Langdon and Sophie realize are the four top members of the Priory. He tries to take the box, to recover property he considers stolen, but Langdon and Sophie overpower him and drive away with the truck and box.

Chapter Themes:
The human world is encoded with meaning.
The centrality of human relationships, especially male-female relationships.
The power of belief, and the need to believe.

Chapter 50
Chapter Characters:
Bishop Aringarosa

Chapter Summary:
In the hills near Castel Gandolfo, Bishop Aringarosa learns he has no cell phone service, which makes him fear that the Teacher will think he's betrayed him.

Chapter Themes:
The power of belief, and the need to believe.