The Alchemyst

The story brings the 15th century French alchemist Nicholas Flamel into the 21st century, where he's a 600-year-old man (who looks to be 50) living in San Francisco, and focus on Sophie and Josh Newman, a pair of teenage fraternal twins who find themselves caught up in an age-old battle between good and evil racing across America, learning the ancient ways of magic even as they're hunted by creatures and beings from the mythologies of a dozen nations. Flamel serves as their teacher and guide.