‘Mortal Engines,’ the latest vision aimed at younga dults

When the whole “Mortal Engines” ordeal is over, it’s a fairly satisfying affair.

“Mortal Engines” — a bizarre-but-intriguing slice of dystopian-future science-fiction aimed primarily at the young-adult set — crams so much into two hours that you wonder if Peter Jackson hadn’t learned his lesson too well. ¶ Jackson, director of the acclaimed “The Lord of the Rings” trilogy of the early 2000s, returned to author J.R.R. Tolkien’s Middle-earth with a trilogy of films based on the author’s prequel, “The Hobbit,” giving audiences three long movies based on a relatively simple story.

Someone unfamiliar with author Philip Reeve’s award-winning 2001 YA novel, “Mortal Engines,” may suspect Jackson and his “Rings”-”Hobbit” writing partners, Fran Walsh and Philippa Boyens, based this movie on a condensed version of the story Reeve tells over the quartet of books that begins with “Mortal Engines.” After all, so much is thrown at us — a frightening vision of the future, a love story, a journey, a mystery to be solved, an epic battle — over the course of two hours that it simply feels like a lot.

However, a little research suggests that, no, this is an adaptation of the first book only, Jackson and company cutting out secondary characters and storylines to fit a version of Reeve’s tale into a reasonable runtime. (With that in mind, perhaps the smarter theory is Jackson was given strict orders from the film’s money men to keep things tight in light of each “Hobbit” film stretching well beyond two hours.)

When the whole “Mortal Engines” ordeal is over, it’s a fairly satisfying affair, although an increasingly convoluted and, at times, silly one that doesn’t live up to its initial promise.

UNIVERSAL PICTURES In “Mortal Engines,” large traction cities such as London, left, hunt down and devour smaller traction towns to strip them of their labor and resources.