42: The Warlock (The Secrets of the Immortal Nicholas Flamel, Book 5), by Michael Scott (2011 hardcover)

While today's best TeenLit weaves in life lessons and critical thinking, it's rare that an author manages to integrate specific educational material into the storyline and still maintain interest, but The Secrets of the Immortal Nicholas Flamel series does just that.  Set in modern time, the book reveals an aspect of the world unknown to most of its inhabitants--the existence of humans made by powerful, god-like Elders.  These immortals come in both good and bad types--and some are a bit of each--based on their affiliation with the Elders.  In the bad camp are the Elders, and thus their loyal Immortal servants, that are not content with the other realms they have created and plot to return to earth and take control.  In the good camp are the Elders and Immortals who oppose such action out of love for humankind. 

Sophie and Josh, teen twins living in San Francisco, encounter this world when they become mixed up in an attack by the "bad" side, led by Immortal John Dee, in the bookstore where Josh is working. The bookshops' owner and wife reveal themselves to be Nicholas and Perenelle Flamel, Immortals who protect the legendary silver and gold twins who will determine the fate of the world.  Sophie and Josh are, of course, these twins.

The primary educational aspect of these books, as introduced above, are the characters themselves.  The Immortals are historical figures, and in getting to know them, readers gain insight to the time in which they were most famous or active.  One by one we meet Joan of Arc, Machiavelli, Shakespeare, Billy the Kid, Virginia Dare, Prometheus, and many others--as well as gods and goddesses of varying mythologies.  Travel between different places and times provides further educational content, all in an action-packed, magical, good-versus-evil series. 

If you get started now, the sixth book (which is clearly coming) may be out by the time you catch up.