Jed Welch, a survivor of the Variant apocalypse, must confront human collaborators who prey on the weak in the ruins of New York City. After the harrowing events of Emergence, Jed finds himself alone. He is found by Staff Sergeant Alexandra Gallegos and her surviving platoon, who are driven by duty and vengeance. Together, they aim to hunt down the human collaborators who aid the Variants. For Jed, this mission is a path to penance and atonement for his past sins.

The narrative of Penance appears to continue the action-packed, post-apocalyptic themes established in its predecessor, Emergence. The focus on military action and the moral complexities of survival in a ruined world suggests a story driven by conflict and character development. Readers familiar with the series can expect a continuation of Jed Welch's personal struggle for redemption, set against the backdrop of a dangerous new world order. The inclusion of military elements and the exploration of human collaboration with monstrous entities points to a gritty and intense reading experience.