Young William Bonney is talked into committing his first train robbery, unaware that his cousin and best friend, Willie Monroe, is now sheriff of the nearest town, and that his fellow robbers are already wanted in four states.

Fifteen-year-old Josh has chosen to side neither with his twin sister Sophie nor with the Alchemyst, Nicholas Flamel, but rather to fight alongside Dr. John Dee and the mysterious Virginia Dare, while the immortal Machiavelli and Billy the Kid follow the Elders' plans to set loose the monsters of Alcatraz on San Francisco and trigger the end of the humani race.