Harry Turtledove's "The Breath of God" picks up where its predecessor, "Beyond the Gap," left off. It starts with Hamnet Thyssen and his companions wandering the Bizogot Steppe seeking allies to fight off the Rulers. Unfortunately, none of the Jarls believe the Rulers pose a threat until they have already been destroyed. The group of companions fight skirmishes against the Rulers, winning some and losing many.

Eventually, they are trapped against the Glacier, and after an avalanche, they climb up onto it to escape from the Rulers. On top of the Glacier, they encounter people who live off the meanest of supplies and food, and have become cannibalistic because of it. They also meet Marcovefa, a Shaman who is more powerful than any of the Bizogots or Raumsdalia. She even thinks she can defeat the Rulers. With Marcovefa's help, they find another avalanche, and climb down the Glacier.

At the bottom, they avoid any Rulers they encounter, and try once again to gather allies. However, the Bizogots still remain stubborn. They barely agree to give food to the group. Several other Bizogot tribes, having fought and been destroyed by the Rulers, joined the growing group. Along with his concerns about the Rulers, Hamnet Thyssen has another worry: that Liv, his Bizogot lover, has been unfaithful to him with Audun Gili, the Raumsdalian wizard. As the companions make their way South, they encounter small bands of Rulers, and manage to defeat them.

Back in the Empire, they work their way to the capital, Nidaros. Unfortunately, at one of the inns they stayed at, Hamnet caught Liv and Audun together. Heartbroken again, Hamnet decides to completely ignore the two. Upon reaching Nidaros, Hamnet approaches Emperor Sigvat II and explains the situation with the Rulers. However, he angers Sigvat, and is sent to the dungeons. He stays there for months, with visits only from his ex-wife Gudrid, come to torment him, and her new husband, Eyvind Torfinn, come to try to get him out. Eventually, Hamnet is summoned to the Emperor again, and finds out that a Raumsdalian Army has been destroyed by the Rulers. Sigvat, with no one else to turn to, sets Hamnet free, and sends him and his companions North to fight the Rulers.

During their trip, Hamnet and Marcovefa fall in love. Upon reaching a small town in the North, Hamnet recruits the town's guards and any soldiers he finds fleeing from the first battle. He also encounters a second Raumsdalian army, which he takes command of. However, will these forces, along with their new shaman Marcovefa, be enough to defeat the mammoth-riding Rulers, or will Hamnet suffer defeat and let the Rulers continue their campaign into Raumsdalia? Read "The Breath of God" to find out.