Iron Codex Books in Order

The Iron Codex starts in the city of Lovecraft, where engines power daily life and fear keeps everyone obedient. Aoife Grayson has grown up under a terrible family pattern: the people in her family go mad when they turn sixteen. As one of the only girls at the School of Engines, Aoife tries to hold to logic, mechanics, and discipline, even while the world around her whispers about witchcraft, monsters, and heresy.

That tension between iron and magic is the heart of the series. On one side are the Proctors, rules, machines, and the official story about disease and madness. On the other are the Thorn Lands, changelings, faerie politics, eldritch creatures, and truths the city has spent years hiding. Kittredge builds an alternate world that feels part steampunk adventure, part gothic horror, and part dark fairy tale.

Aoife is a good guide through it because she never begins as a wide-eyed fantasy heroine. She is practical, frightened, brilliant, and already carrying more family history than any teenager should. Once the truth starts to crack open, she has to do more than survive. She has to decide what she owes to her family, her city, and the parts of herself she has been taught to fear.

Nothing stays mechanical for long.

As the trilogy moves on, the scale widens from one city and one cursed family to the future of the Iron Lands themselves. Gates between worlds break down. Old lies fall apart. Aoife learns that what she thought was inherited madness is bound up with her own nature, and every answer drags in new danger. Friends and would-be protectors complicate things further, because in this world love and loyalty rarely come without strings.

The tone stays darker than a lot of young adult fantasy. There is adventure, romance, and big worldbuilding, but there is also grief, body horror, and a constant sense that knowledge has a price. If you want a series where gears, faeries, and family curses all belong in the same room, The Iron Codex is a very good place to start.