Twelve is a popular number. Eggs come in twelves. Doughnuts come in twelves. Monkeys come in twelves. And, it seems, members of top-secret societies also come in twelves. It's kind of a perfect magical number.
In The Paladin Prophecy, Will discovers a group called the Knights of Charlemagne. Guess how many there are. We'll give you a hint: greater than eleven, fewer than thirteen.
Twelve. There are twelve.
Jolly Nepsted explains the significance of the twelve:
Twelve is a scared number. […] Wholeness. Unity. Twelve signs of the zodiac. Twelve tones in the musical scale. Twelve face cards in a deck. Twelve on a jury. Twelve nights of Christmas. Twelve labors of Hercules. Twelve men on the moon. Twelve petals of the unfolding eternal lotus. Twelve hours of darkness, twelve of light. Twelve tribes of Israel. (30.14)
If you notice, Jolly mentions twelve different groups of twelve. That's a lot of twelves. He says "twelve" so often that it stops looking like a real word. Twelve twelve twelve twelve twelve twelve twelve twelve twelve twelve twelve twelve.
Incidentally, the twelve paladins are actually part of the legends surrounding Charlemagne's re-conquest of Spain from the Umayyad Empire in the 8th century.
Twelve manifests itself at other points during the book, too. The bad guys' tracking bug has "twelve spidery legs" (1.85). When Nick fights Todd and his men, he comments, "Twelve against one" (30.112). Dave grants Will level 12, which is the highest level of "security clearance" (37.19) in his mysterious organization. And inside Lyle's room is a shelf "filled with rows of twelve-inch spiral notebooks" (31.92). There must be something important in them, but Will doesn't think to look.
Aren't you paying attention Will? Twelve always means something.