The final book in the "Secrets of The Immortal Nicholas Flamel Series," finds Nicholas and his sorceress wife Perenelle back in San Francisco to defend the city against savage beasts and monsters that have been transported to Alcatraz Island and will soon be released to destroy humanity. While Sophie and Josh the twins of legend known as the Silver and the Gold, have been sent back through a portal in time to ancient city of Danu Talis at the request of Osiris and Isis. The world as it has been known is coming to an end both in San Francisco and on Danu Talis leaving the legend to explain humanity's fate "The two that are one must become the one that is all. One to save the world, one to destroy it."