"In the Valley of Gods is a single-player first person video game set in Egypt in the 1920s", reads the official site's FAQ. The game's first trailer, revealed tonight at The Game Awards, comes with a 2019 release date attached. Though no dialogue was heard in the above trailer, we see that you play as one of two female explorers travelling through an ancient Egyptian temple. So Firewatch fans anxiously anticipating Campo Santo's next game have a nice long wait ahead of them. Campo Santo said that the game is expected to release on Mac, Linux and Windows PCs.
In the Valley of Gods will arrive sometime in 2019.
"In the Valley of Gods" isn't a direct sequel to "Firewatch", but it's a bit of a spiritual successor.