Locked beneath the scarred surface of a hostile planet, the last members of a human pilgrimage made a profound discovery that would save them from extinction. Now, generations later, that epiphany has given birth to the sprawling city of Nox. Isolated, the city has developed technologies to subsist in their alien environment. A rigid caste system, overseen by the Eternal Council, dictates every aspect of life within the city to ensure that humanity continues to flourish.

The metropolis has survived starvation, natural disasters, and wars with the inhuman natives of the Sunless Lands. But can it survive its own secrets being discovered by a group of rebels just desperate enough to use them?