Storms hit England and the Danish long ships that were sent to aid Guthrum are destroyed along the shore. The peace still broken, Alfred splits his army: half to meet Guthrum (in Holdenhurst, led by Alfred), and the other half to meet Ubba (in Cynwit, led by the two Oddas and Ealdorman Wulfhere).
At Cynwit Hill, the Saxons set up camp and bide their time on the high ground, waiting for Alfred's reinforcements like sitting ducks. Ubba and his men camp below, intending to strike sooner rather than later knowing food and water supply is short on the hill. But at negotiations, Uhtred taunts Ubba and provokes him into thinking the gods are against him for not avenging Ragnar's murder, and in so doing, buys the Saxons a little more time. Uhtred then urges Lord Odda to strike that night after he sets fire to the long ships while the Danes scurry in disarray. Odda must keep his word and not abandon Uhtred in his one-man mission, despite his son suggesting they flee Cynwit to meet with Alfred and form a larger army.
Taking inspiration from a grease fire, Uhtred prepares wads of pig fat soaked in oil and sneaks into the Danish camp, successfully setting fire to all their ships. When fleeing, he is spotted by Storri and Ubba challenges him to a man-on-man fight to the death, from which he cannot back down.
Both men fight without armor, using only a shield and one weapon: sword for Uhtred and axe for Ubba. Things do not look good for Uhtred as he's knocked to the ground defenseless, but when Ubba raises his axe to deal the final stroke, Uhtred grabs a nearby shard from his splintered shield and stabs Ubba above the knee. In Ubba's moment of pain, Uhtred reaches for his sword and in one fell movement, slices Ubba's Achilles heels open. Ubba falls forward as Uhtred makes another slice at his neck. Respectful of his opponent as a warrior, Uhtred places the battleaxe in the dying Ubba's right hand and sends him on his way to Valhalla.
Uhtred looks up from his duel and realizes he is surrounded by angry Danes, but men suddenly emerge from the shadows and surround Uhtred to form a shield wall. Odda has kept his word and the Saxons are able to defeat the Danes. In the aftermath, Lord Odda has been gravely injured and his weasel son rides immediately to Alfred to claim credit for the victory with Ubba's axe as proof. Uhtred is more concerned with going to his wife and son, whom he has not seen since his departure to Wareham as a hostage. Together, they ride to Winchester where Uhtred barges in on Alfred's silent victory prayers, maddened that his efforts at Cynwit have gone unrecognized (though Leofric did warn him). But all Alfred sees is the Dane's continued insolence, and even moreso in the presence of God. He punishes him by forcing him and Æthelwold (who has absconded from the monastery) into penance by grovelling on their hands and knees through the city of Winchester. Uhtred has reached a new level of humiliation under Alfred's service and can no longer hold respect for the Christian religion which, in his eyes, is not able to serve justice the way justice should be served.
Upon returning home to Lyscombe, Uhtred notices the plump Oswald dragging a felled tree to the lumber yard. Suspicious of Oswald pocketing a profit from timber that rightfully belongs to him, Uhtred questions him. Oswald flees, but he's not quick enough and is run down and trampled by Uhtred and his horse. This, along with Uhtred's recently peaked hatred towards the Saxon-Christian way of life, causes irreparable damage between him and his wife.