The two that are one must become the one that is all. One to save the world, one to destroy it. 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 they are not stopped, they will destroy everyone and everything in their path. But even with the help of two of the greatest warriors...

In his first journal, middle schooler Rowley Jefferson, Greg Heffley's sidekick, records his experiences and misguided decision to write a biography of Greg, who, in his own mind, is destined to become rich and famous.