Chapters 11-20 Summary
At the crime scene in the Louvre, Sophie puts the 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.'" For example, 1 + 1 = 2, 1 + 2 = 3, 2 + 3 = 5, and so on.
Langdon offers excuses after he gets off the phone, saying there was an accident requiring him to fly home, and asks to visit the restroom. While he is headed there, Sophie leaves. Fache goes to make a phone call, leaving Collet tracking Langdon...
(The entire section is 1050 words.)