Next December, there'll be a new entrant into the end-of-year, blockbuster science fiction movie category: the Peter Jackson film Mortal Engines. A teaser trailer for it dropped just before the holidays, and there's really only one thing you need to know about it. Driving cities. Driving cities! Now, I know the movie is based on a book series, which probably has a lot of detail about these giant ambulatory dwellings. But I like to try and see what I can figure out just from the trailer itself.