Iron Gold will be the first book in a new trilogy set in the same universe as the Red Rising trilogy.
In an interview on the Hallmark channel, Pierce Brown stated that the story will be set approximately 10 years after the events of Morning Star. 
In an interview with Entertainment Weekly, Pierce explains more of the plot of the book:
The new Solar Republic, led by Darrow and Mustang, has replaced the Society on Mars, Earth, and Luna, and is locked in an existential struggle with the remaining Golds of the Core. A decade-long peace still exists between the Republic and the Golds of the Rim worlds, but something stirs in the darkness out beyond the asteroid belt.Also stated is that there will be four points of view, including that of Darrow, with two completely new characters.
- ↑ https://www.youtube.com/watch?v=BPQDBnJnBzQ&feature=youtu.be
- ↑ http://www.ew.com/article/2016/12/15/pierce-brown-iron-gold-cover-plot-new-red-rising-trilogy
- ↑ http://www.usatoday.com/story/life/books/2016/02/17/exclusive-pierce-brown-morning-star-red-rising-usa-today-best-selling-books/80451454/
- ↑ https://www.facebook.com/PierceBrownAuthor/posts/980247885441791