Adapting a full novel into a single film is a fool’s errand. While it can (and has) been done well, all too often the full breadth of the story is better suited for the page than for the screen. Mortal Engines is a prime example of a potentially great films that had all the imagination of the novel, but failed to successfully adapt the story.

Based on the first book of a series by Philip Reeve, Mortal Engines takes place on a post-apocalyptic Earth. After the 60 Minutes War nearly destroyed all life and wiped out much of our technology, the remaining human outposts gathered up what was left and made their cities mobile. These massive mechanisms can range from small and swift scavenger ships to one that holds all of London. The roving metropolises leave massive tracks in the soft soil as they cross the barren landscape looking for resources and survival.

Sadly, a small Bavarian mining town is the resource that London comes across on one fateful day. As soon as the small village is spotted by the behemoth, they pick up their mines and London gives chase. Within the first five minutes of Mortal Engines, we see not only two different types of these massive creations, but we also see how people living on them cope with the constant movements, and most importantly we see the scale. Describing London as “gargantuan” barely gives any service to how truly immense this vehicle is. It’s able to ingest an entire town within moments and without slowing down, and without life onboard pausing to notice.

The design of the world within Mortal Engines is the true strength of the film. The sights of each location, as well as the machines that take us there, are complex, well-realized, and fascinating to behold. Simply existing in this world and getting to see the ways that life has adapted to constant motion is a joy.

The plot, however, keeps trying to get in the way of enjoying the movie, and often succeeds. Like many book adaptations, this film suffers from trying to do too much too quickly. We’re introduced to too many characters and not given enough information to care about them all. For example, there are Wanted posters all over London looking for Anna Fang (South Korean pop star Jihae), who appears to be one of the more interesting people on the planet, but we never learn what she did to earn her fugitive status. Her whole crew of bandits seem like the kind of group we’d want to get to know too, but they’re introduced and then quickly sent off to save the world.

The glaring exception to this pattern of rushing through the introductions is Hester Shaw (Hera Hilmar). Her story is central to the plot of Mortal Engines and she’s largely the driving force behind it, but her motives are varied and complex, which leads to unnecessary bloating. While it may work better in a 320-page book, including two weepy origin stories for a single character is not evidence of strong editing skills.

Mortal Engines creates a beautiful, dangerous, and escapist world, but it suffers from trying to do too much with characters we barely care about.