'One part The Da Vinci Code, one part The Name of the Rose . . . The Rule of Four is as much a blazingly good yarn as it is an exceptional piece of scholarship... A smart, swift, multitextured tale that both entertains and informs'

   San Francisco Chronicle

Tom Sullivan,about to graduate from Princeton,is haunted by the violent death of his father,an academic who devoted his life to one of the rarest,most complex books in the world,Coded in seven languages,the Hypnerotomachia Poliphili,an intricate mathematical mystery and a tale of love and arcame burtality,has baffled scholars since 1433.

Tom"s friend Paul is similarly obsessed and when a long-lost diary surfaces they finally seem to make a breakthrough.But only hours later,a fellow researcher is murderde and the two friends suddenly find themselves in great danger.Working desperately to expose the book"s secret,they slowly uncover a Renaissance tale of passion and blood,ahidden crypt and a secret worth dying to protect...

Historical Note

Prologue

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Chapter 10

Chapter 11

Chapter 12

Chapter 13

Chapter 14

Chapter 15

Chapter 16

Chapter 17

Chapter 18

Chapter 19

Chapter 20

Chapter 21

Chapter 22

Chapter 23

Chapter 24

Chapter 25

Chapter 26

Chapter 27

Chapter 28

Chapter 29

Chapter 30

Author"s Note

Acknowledgments

The Asssassini

The Bridge of Sighs

Blindsighted

A Faint Cold Fear