When the anomaly appeared at the Earth's core, the Substratum Protocol was initiated. You are the best and brightest scientists we have left, our last hope to stem the apocalypse. You are the Substratum Expedition Team. Descend. Learn. Survive.

The Codex includes new content to bring different styles and settings to your Monster of the Week games. It’s written by Michael Sands and Marek Golonka, and being developed in partnership with Evil Hat Productions.

N.K. Jemisin’s multiple Hugo Award-winning Broken Earth Trilogy comes to tabletop RPGs in The Fifth Season Roleplaying Game!