The Necromancer, book four in Michael Scott's "Secrets of the Immortal Nicholas Flamel" series, brings the immortal Flamel (The Alchemyst) and teenaged twins, Sophie and Josh, back home to San Francisco, where they meet up with the sorceress Perenelle, Flamel's wife, who spent the last book escaping from Alcatraz. Time is running out for the Flamels; it's now been six days since their foe Dr. John Dee (another immortal) ran off with the Codex, the book of Abraham the Mage that keeps them young, and they are aging fast. The twins, who have been learning the Elemental Magics over the course of the first three books, are worried about getting into trouble for basically disappearing for days, so they check in with their guardian, Aunt Agnes. But Scott doesn't let them settle in for long. True to the break-neck pace of this series, they are quickly pulled back into the action when Sophie is kidnapped by a redheaded vampire who bears an eerie resemblance to one of their recent allies, Scathach, who disappeared with Joan of Arc in the last book. The Necromancer introduces readers to even more infamous immortals, while keeping up with favorites from past books--Machiavelli, Shakespeare, Billy the Kid. As the characters accumulate, so do the opportunities for hair-raising conflicts and insane reveals. Scott manages their multiple story lines with a sequence of cliffhangers that keep it a really fun read even as he is piling on the history and mythology, taking readers further into the secrets that will bring the whole story together. As the characters hurtle toward a conflict that could bring about the end of the world, we can't wait to see where they'll go, what they'll learn, and who they'll meet next. (Ages 12 and up.)