'Mortal Engines' screenwriter Philippa Boyens "worried" if fans would "understand" the flick.

Philippa Boyens

Philippa Boyens

The Academy Award-winning producer has confessed that the blockbuster "was not an easy day at the office" because the project took a lot of time to get just right.

Speaking to Collider about the adaptation process, Philippa said: "Any work of such vast imagination is not an easy day at the office, it's a puzzle and you've got to make the pieces work and you can't overwhelm the story just because of the great visuals and vice versa, and the main thing I worried about was if people would understand this world. It's little things like that of how you're going to get people into the world."

Philippa worked on the movie adaptation of the sci-fi fantasy book that sees the protagonist of the story, Tom Natsworthy - played by Robert Sheehan - join forces with a young woman (Hera Hilmer) from an area known as the Outlands, to discover a mystery that could change the world they live in.

And Philippa is no stranger to the adaptation of fantasy novels as the screenwriter worked on 'The Hobbit: An Unexpected Journey', 'The Hobbit: The Desolation of Smaug', and 'The Hobbit: The Battle of the Five Armies' in 2012, 2013, and 2014 respectively.

She added: "These books first came to us about ten or twelve years ago actually, and they ended up being shelved because of the rights to The Hobbit becoming free, so we ended up doing that. When it came time to do this and finally think 'Do we want do it? Are we gonna do it? If we don't do it we've got to do it now.' What was interesting was, it felt like it was the right time to do it, and it was like fate had played a hand somehow. We never set out to write films that are issue spaced or sending some kind of message, so to speak because we wrote the scripts three years ago. What you find in the process of making films is they become more and more relevant naturally because they're being made in that moment and there become moments where you want to reflect what's going on in the world. The whole notion that mankind can destroy itself, I mean that is a theme that's run through in the history of mankind forever."