Fifteen-year-old twins Sophie and Josh Newman continue their magical training in Paris with Nicholas Flamel, Scatty, and the Comte de Sant Germaine, pursued by Doctor Dee and the immortal Niccolo Machiavelli.

Nicholas Flamel and teenaged twins Josh and Sophie Newman return to San Francisco where a weakened Flamel reunites with his wife, Perenelle, hoping to use his remaining power to prevent the monsters on Alcatraz Island from escaping. Meanwhile, Dr. John Dee and Machiavelli continue to seek power and the twins desperately try to determine who they can trust as they search for Scatty and an immortal who can teach Josh the magic of fire.

San Francisco: Nicholas and Perenelle Flamel have one day left to live, and one job left to do. They must defend San Francisco. The monsters gathered on Alcatraz Island have been released and are heading toward the city. If theu are not stopped, they will destroy everyone and everything in their path. But even with the help of the greatest warriors from history and myth, will the Sorceress and the legendary Alchemyst be able to defend the city? Or...