From amazon.com:
The Knights of Crystallia is the third action-packed fantasy adventure in the Alcatraz vs. the Evil Librarians series for young readers by the #1 New York Times bestselling author Brandon Sanderson. These fast-paced and funny novels are now available in deluxe hardcover editions illustrated by Hayley Lazo.
In this third Alcatraz adventure, Alcatraz Smedry has made it to the Free Kingdoms at last. Unfortunately, so have the evil Librarians--including his mother! Now Alcatraz has to find a traitor among the Knights of Crystallia, make up with his estranged father, and save one of the last bastions of the Free Kingdoms from the Evil Librarians.
"Beneath the wild humor, there are surprisingly subtle messages about responsibility and courage." - School Library Journal