We begin by picking up on an unresolved previous issues from Kjartan's spirit journey. He took two branches from the Tree of Knowledge, one of them about the history of Steinthor of Hvalrik. From that branch, he learned that Steinthor was indeed Stein the Cruel of Tjaraholt. In 1347, a few years after the establishment of Salem, there was a war with the Massachusett. In response to a vicious raid, Steinthor went with his nephew Thrand and a small army and wiped out a Massachusett village to the last man, woman, and child. He came under a death-curse as a result, but he made a deal with the horned serpents. The curse would still apply (as all fates do), but it would be put off for a long time. The curse was to doom all those in his community -- that he would see all of them come to a horrible doom.
Riding away from the slaughter, Steinthor and Thrand and the men forded a stream. Thrand was strangely sucked under to drown, his body never found. However, Steinthor came under suspicion because he never looked back and instead forced his horse out of the water as quickly as possible. Within a few months, he left Hvalrik for the Commonwealth, essentially forced out by his brother Thorstein (Thrand's father).
Meanwhile, the long winter passes. Kjartan ponders this. He eventually shares it with all, and in fact composes epic poems of the story of his spirit journey and the history of Steinthor. Melnir and Silksif stay at Brygjafael for several weeks after the ceremony. Eventually, Melnir goes back by ski to Raudarbank at the start of February, while Silksif waits for gentler weather and the river to clear.
The river becomes passable in the early spring. Silksif prepares to leave, but Kjartan and Poul decide that they would like to consult with the horned serpents concerning Steinthor, and ask for her assistance. They form a plan to go back to the cave where they confronted them last spring, wishing to bargain regarding the curse on Tjaraholt. Kjartan goes across the river to Skallagrim to ask for him to come, him having found the cave the last time.
At Grimholt, Borgny and her newborn child had just returned from wintering at Grjotvogur (Rockaway). Borgny learns from Skallagrim what happened with her daughter Vagnhild. She agrees that it was for the best, with quiet regrets about the way things went and hopes to do better with her new child. With the news from Kjartan, Skallagrim decides to take with him the head of the horned serpent he had chopped off the last time.
Kjartan, Poul, Maushop, Silksif, and Skallagrim then go to find the cave where Maushop had gone. Entering in, they descend to the underground river. There, Maushop fearlessly walks up to the water and makes a wide swirl with his arm. The ripples move out, but instead of lessening they grow greater, eventually resolving into the wake of serpents under the water.
One horned serpent then comes out and speaks first with Maushop, and then with Silksif. While others speak, he tends to speak only with her and Maushop -- only acknowledging others when directed to do so. Roughly, they explain that they have taken on enforcement of the death-curse laid on Steinthor -- using words suggestive of the Icelandic idea of buying a godi position or someone else's lawsuit. In a roundabout way, they say that the curse will be doom to all those of Steinthor's "house". Here they are not perfectly clear, especially given differences between Lagakin and Vinlanders. By sacrifices (including that of Thrand), Steinthor put off the curse but it must still come true. Thus, they say that there will be trouble around the house of Tjaraholt and advise Silksif to keep away from her land until it is past.
Skallagrim at this point offers them back the head of the serpent which he killed the last time. He throws it in the water, and it sinks slowly. They thank him and offer him reward. He says that he wants to kill Ivar -- and the serpents happily grant that, prophesizing that it will indeed come to pass.
Lastly, Poul asks what they have to do with fires. He has in the back of his mind, it seems, some plan for harnessing the serpent's fire for his own forging processes. They offer to work with him on this, making hot fires for making weapons. Maushop pales as on of them looks at him. Poul notices, but accepts it when Maushop says it was only a feeling he got. They offer that Poul can forge again, if Maushop will make a hammer for him. This will be like the prophecy-axe which he forged for himself. Still suspicious but uncaring, Poul accepts.
They leave the cave to return to Brygjafael, disturbed at what they had found.