Parents who want to inspire their tweens and early teens to do something other than play with the Xbox over the holidays might try giving them Scott Westerfield's "Leviathan" from Simon Pulse, Simon & Schuster. Okay, it's not about diving per se. However, it may captivate young minds with its Jules Vernesque sci-fi retake on World War I as fought with a 19th century version of high technology. It starts with the assassination of Archduke Franz Ferdinand, of course, and the escape of his fictionalized son Aleksandar. He meets Deryn, a Scottish girl who has disguised herself as a boy to join the British Air Service. Together, they get swept into the world of war fought with zeppelins, walking machines and other half-beast half-machine creatures. One of them, the leviathan, is a dirigible that was grown on the genetic chassis of a whale. Heroes and heroines hark back to Victorian days of exploration for adventure and a strong sense of what is proper. It's a fast-paced plot that caroms between opposites of boy / girl, commoner / aristocrat, man / machine, Darwinists / and bio-engineers, which presents an underlying theme of acceptance of others' ideas and people.