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How 'Mortal Engines' Crafts an Interesting Fictional Setting

Immediately on starting ‘Mortal Engines’ you’ll be confronted with the book’s unique dystopian landscape – a world where cities roam a bleak muddy wasteland eating each other, sending great pillars of smoke into the atmosphere as airships made of scrap metal fly about overhead.


The word for such a setting is steampunk, and it’s been one of my favourite aesthetics for as long as I can remember. And yet, this is the first book I’ve actually read within the genre. Well, other than ‘The Steampunk Bible.’ But the first fiction book, in any case.


When it comes to the fantasy and science fiction genres, there is one major aspect of the story that its author has to get right, and that is the worldbuilding.


Fans of both genres have come to expect this element of the story to be a certain level of quality, whether you focus on breadth or depth. We need to see landscapes, civilisations, technology or magic, cultures, each one finely crafted and feeding into the others.


With all that detail, all that raw creativity pulsing inside of a book’s pages, you might expect a certain length too – a several hundred page epic, itself only the first in a series of twenty additional sequels. Understandable… but unnecessary.


‘Mortal Engines’ ends at an easily digestible 293 pages – it’s a short book. And combined with its simple, YA writing style, it’s also what I’d call an easy read type of book. This means the book is easy to pick up, easy to keep reading, and before you know it you’ve turned the last page.


But more importantly, it proves that quality worldbuilding has nothing to do with quantity. Instead, it demands three things of the writer:


  1. A rich imagination, able to produce at least one unique idea for a setting.

  2. The talent to unravel this idea and expand it into not just a premise, but an entire continent (or more!) of culture and technology.

  3. The ability to hold back on exposition, and deliver this setting as *briskly* as possible.


I believe that last point is the key to ‘Mortal Engines’ having such a compelling setting. Which is a good thing, because the first two are damn hard.


Luckily, that third point is actually pretty easy, and this book shows us exactly how to do it.


But before getting into that, I want to briefly touch on those other two, because even accepting point 3 as more important, that shouldn’t discourage you from diving into the others. So, unique ideas. Where do we get them?


It’s a common question aimed at writers and, to roughly quote Neil Gaiman, “Nobody knows.” The more pressing issue is that you can recognise them once they come along, and put them down on the page.


The thing about unique ideas is that there isn’t just one way to go about them. In fact, if there was, there’d be no unique ideas left to have because some pest would have stolen them all.


The only advice anyone can rightly give for this point is that every writer, by the very nature of being their own person, does in fact have a unique idea. I guarantee you do. And a writer’s voice is often the place this unique idea comes from. But I’ve already spoken about voice in a previous essay, and I’m sure I will again.


For now, point 2. How do we expand on an idea once we have it? Well, follow in the footsteps of ‘Mortal Engines’! In my view, what the author needs to do is write down their original concept, whatever it is, and ask themselves to list as many answers as they can think to the following question:


Supposing this unique idea was true of the world – what would this affect?


If you’ve got a truly great idea, the answer is probably, “Just about everything.” But that’s not a helpful answer. You’ve got to get more specific than that. The first step is deciding what type of thing your idea is, then you need to think about all the other types, and how your idea affects them. Here are some examples of the kinds of ‘types’ I’m talking about:


Technology, Science, Medicine, Culture, Religion, Politics, Art/Media, Architecture, Sport, Education, Policing, War, Journalism, The Natural World, The Galaxy/Intergalactic Races.


There are probably more ‘types’ you can come up with, and each one of those types has a large number of items within it. But that should give you a good start.


Now, a well-crafted setting doesn’t need to delve into every one of those, or indeed even half of them, probably. But the more of those elements of the world you at least consider with every ‘brick’ of your worldbuilding, the more fleshed out it is going to feel when we read your story.


I don’t know if Philip Reeve actually followed this brainstorming pattern when writing ‘Mortal Engines’ of course, but I do know he would have found success using it, and it was ‘Mortal Engines’ that inspired me to come up with it in any case.


With that out of the way, we can finally get into the third point:


How does a writer hold back on exposition, and deliver worldbuilding more briskly?


If you don’t mind, I’m going to split up my answer into two sections.


Section 1: How do I hold back on exposition?


The first thing to be aware of here is that, like all elements of storytelling, exposition is not inherently bad. When we say a book sucks because of the exposition, what we’re usually talking about is either bad exposition, or too much exposition.


The most obvious question now then, is what’s a good exposition, and when is too much?


Well, you know it’s too much when it gets boring or frustrating. Very subjective, that, of course, and not easy to tell. But a good rule of thumb is that you shouldn’t be waffling on about how exactly your ninth wonder of the world was constructed for more than a paragraph. Or at least, not without good reason. (I’m personally of the opinion that all ‘rules of writing’ have exceptions.)


As for what makes good exposition – this, finally, brings us onto that second section of the third point.


Section 2: How do I deliver worldbuilding more briskly?


I’m answering two questions in one stroke because I consider it the same general principle. That principle is this:


Worldbuilding should be introduced when it is relevant to a character, and only then.


This can still mean a couple of different things, so let me bring this essay back around to the subject book – ‘Mortal Engines.’


In the beginning, the main character, Tom, is working in a museum. During this time he is cleaning and looking around at many of the items inside the museum. This lends itself nicely into some prose about the past – our present day – and more importantly, the things Tom has been taught about it. This reveals not only the past, but also the education and scientific and archaeological research of the setting, as well as the brainwashing of London’s residents, and our main character’s own thoughts and feelings about the past.


Another example – there are several moments in the book where one or more main character is walking – or running (or flying) – through the setting. It then makes perfect sense to describe the mud they’re slipping into, or the steam in the air blocking their view, or the mobile, cannibalistic cities chasing after their hometown. Which not only gives us a good idea of how the city is made up, or what the wasteland looks like, but also how it got here, who got it there, why they did it, and how it’s benefitted or ruined various characters’ lives as a whole.


Finally, the other place to add worldbuilding is through exposition. That’s right, that thing I told you not to overuse. A lot of writers will tell you that exposition is okay as long as someone doesn’t know that thing being exposited. I… agree, to an extent. I think it’s okay for your more knowledgeable adult character who’s been flying around this world for thirty years to explain a thing to your naïve teenage character who hasn’t.


I still think that’s a weaker way of building up the setting though.


And the reason ‘Mortal Engines’ impressed so much is because the worldbuilding comes primarily through the senses of our three perspective characters – the cannibalistic cities are introduced to us because someone saw an ongoing hunt. The way the city of London is constructed we know because someone was making their way through each level, looking around all the while, listening to the sounds of the noisy, predator city of London. We’re aware of the vast wasteland outside each city because our characters were stuck there for a while. And we know about the hot, humid underbelly of London because our characters were made to go traipsing down there for a chapter every now and again, and they *felt* that heat and humidity.


This brings me back to what I said earlier – build up the setting when it’s relevant to our characters. And when is it relevant to our characters?


Well, it’s relevant when they actually have to engage with a piece of the worldbuilding.


And how is ‘Mortal Engines’ able to deliver so much depth and complexity in such a short page count?


Well, it’s able to do that because it doesn’t follow the formula of [exposition, action, exposition, action].


Instead, the action directly involves the exposition… I mean the worldbuilding. And it does this through characters we care about, characters who feel real – and they feel real because they’re directly interacting with the worldbuilding.


It’s a circle. A circle of worldbuilding and character development.


And there are no two things that scifi/fantasy readers like more.

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