“London is on the move again.” It’s this curious line, branded across the back cover, that attracted many a young reader to Philip Reeve’s 2001 novel Mortal Engines.

Within its pages, the vision of a post-apocalyptic world ravaged by a mysterious event known as the Sixty Minute War, in which many of the world’s cities have become mobilised; now transformed into great mechanical beasts on wheels, known as Traction Cities, roaming across the land in search of smaller cities to devour for their resources.

Within this world unfolds a story of revolution, justice, and revenge: as a young man, Tom Natsworthy, is sent to London’s bowels to help dismantle conquered settlements, only to cross paths with Hester Shaw, a young woman hell-bent on killing the man she claims destroyed her life.

Mortal Engines gears up now for its first cinematic adaptation; with a screenplay by Lord of the Rings trio Peter Jackson, Fran Walsh, and Philippa Boyens, the film marks the feature debut of Christian Rivers, who has worked alongside Jackson as a storyboard artist and visual effects supervisor ever since 1992’s Braindead.

It’s been a long journey for Mortal Engines’ creative team, as reports originally surfaced back in 2009 that Jackson was developing the project, with the rights to the book acquired several years earlier. However, the film ended up on the back-burner after Jackson stepped in to direct The Hobbit trilogy, in light of Guillermo del Toro’s own departure from the franchise in 2010.

But, in a way, Mortal Engines may have benefited from the passage of time. A chance, not only, to see visual effects technology continue to flourish, rendering London’s roaming metropolis in ever-more realistic detail, but to find breathing room outside of the deluge of young adult, dystopian films that’s only recently thinned out.

For Rivers, also, it arrives at a time when Hollywood seems to have reached peak saturation when it comes to sequels and remakes.

As he notes: “I personally just felt like audiences need something new and exciting and fresh. Mortal Engines is a new universe with new characters and it feels like the right time for that. We are living in a time with lot of franchises, sequels, and remakes; hopefully, Mortal Engines will provide a wonderful story, a wonderful cinema experience that is unlike anything seen before.”

The film’s first trailer, in fact, makes immediately apparent how visually unique Mortal Engines promises to be: the novel’s inherent steampunk DNA - all those engines and airships - here finds a distinct splash of almost Blade Runner-esque dystopian retro-futurism.

All taken straight from Reeve’s own words, as Jackson enthuses: “Philip Reeve did a lot of the heavy lifting in his novels. He developed such rich imagery and wonderful characters for Mortal Engines.”

“That is one of the things that appealed to us - is that it is such a unique world,” he adds. “I’ve never seen a city on wheels that is twice as large as the biggest cruise ship in the world. We are creating a visual world that you have never actually seen before.”

It’s a design approach tied deeply into the world’s own rich, textured history, as Rivers explains: “In designing the future, we had to imagine most of our world has been destroyed and grab certain iconic things from our world that might have survived - then imagine what a future society would have extrapolated from those.”

“If we were walking among the ruins and found remnants of our civilisation, what importance would we put on them? That is how we approached London, which is why you have St. Pauls [which sits at the very top of London’s machine], which was possibly the most intact, the lions, and the Union Jack. All of these things which had been given prominence have been reinterpreted on the giant Traction City of London.”

Which, of course, leads directly to the story’s immense scale. Rivers notes over 70 sets were built for the film, adding: “We wanted to have something from inside the film for the actors to play off. Scale is one of the big challenges in this film. London is huge and constantly moving so that has been a real challenge.”

Though the impulse for spectacle might tempt a filmmaker to reveal what the cataclysmic Sixty Minute War actually was, Rivers promises the characters will still only have “fragmented information” about the event which occurred thousands of years earlier.

Keeping true to the spirit of Reeve’s words is, of course, a priority here. Jackson notes the biggest departure is simply that the main characters have been aged up slightly, here played by actors Robert Sheehan and Hera Hilmar.

“Instead of making a YA-orientated film, we have made it also appeal to an older audience,” he says. And what should fans get particularly excited about? Rivers has a hunch it’s Shrike, played by Stephen Lang, resurrected from the dead and transformed into a ruthless killing machine. Guaranteed, though, there’ll be plenty of more surprises tucked inside this vast, fascinating world.