Most of my writing ideas don’t come to me in a coherent fashion, and the magic system for Iron Cast is no exception.
Here is the (rambling) thought process I went through one afternoon, just as I was settling in for a nap: Science is pretty cool. Think about all the cool stuff Science can do. In fact, some of the stuff Science can do is so unbelievable that before Science was a thing, people thought it was magic. Fields like chemistry are still kind of like modern magic, if you think about it. So if chemistry is the magic of Science, then why isn’t there a magic of art or literature or music? What if there was? What if musicians, poets, painters, thespians, and other types of artists had their own kind of magic, made possible by their natural talents and an element in their blood that was yet to be explained by Science?
The more I explored the idea, the more it made sense. A talented musician can evoke emotions with their instrument, and a talented writer can create imagery so vivid that you can practically see it. If there was something extra special about a person’s genetic makeup, then maybe the effects of their talent could be more literal. Maybe a musician could make you feel any emotion they wanted you to feel, and maybe a poet could create an illusion so potent that you’d believe it was real.
Once I had the general concept of the magic system, everything else started to fall into place. I decided that the difference in the genetic makeup that made hemopaths special would be a yet-unidentified element in their blood (hence the term “hemopaths”). This element reacts adversely to iron, making it exceedingly painful for hemopaths to be anywhere near iron or—to a lesser extent—its alloys. At one point in the novel, Corinne likens the feeling to that of two magnets repelling each other, as if every drop of blood in her body was one magnet and the iron was the other.
This peculiar weakness of hemopaths was inspired by the old legends of fey being driven away by iron. I reasoned that hemopaths would have been in existence long before their abilities were widely known, so who’s to say, in this alternate world I was creating, that they weren’t the root of these legends?
For me, the worldbuilding was probably one of the most enjoyable parts of writing this novel. I wanted this Boston to feel very like our own world, but at the same time, utterly alien. There are the same prejudices and systems of discrimination that plague our world, just with the added layer of the “hemopath problem.” Thanks to an over-ambitious con that humiliated a councilman (which our heroines may or may not have masterminded), hemopathy for public consumption has been recently illegalized. This has given rise to underground hemopath clubs where patrons can be entertained by wordsmiths and songsmiths—for a price. (This setup, of course, is a harbinger of the speakeasies that come out of Prohibition, which looms on the horizon.)
Hemopaths have more than the law to fear. Ordinary citizens wear iron jewelry as a means of detecting hemopaths who are trying to pass unnoticed. There are vigilantes known as ironmongers kidnapping and murdering them in gruesome ways. And then there is the Haversham Asylum for Afflictions of the Blood. This iron-free prison was built as a humane alternative to jail for criminal hemopaths, but the problem is that people keep getting dragged there without a trial. And no one ever seems to come back.
Striking a balance between the glamor and excitement of the clubs and the terrors that hemopaths face in the outside world was one of the most challenging and rewarding aspects of this novel for me. If readers are able to lose themselves in it for a little while, then I’ll consider it a success.