The War of the Five Kings is slowly coming to its end. Stannis Baratheon has gone to the aid of the Wall, where Jon Snow has become the 998th Lord Commander of the Night's Watch. King Tommen Baratheon, Joffrey's eight-year-old brother, now rules in King's Landing under his mother, Cersei Lannister. Brienne, the Maid of Tarth, is on a mission to find Sansa Stark, aided by Jaime Lannister. Sansa Stark is hiding in the Vale, protected by Petyr Baelish, who has murdered his wife Lysa Arryn and named himself Protector of the Vale and guardian of eight-year-old Lord Robert Arryn.
Pate, a young apprentice at the Citadel in Oldtown, is studying to become a maester. He has stolen an important key to a depository of books and records at the request of a stranger in exchange for a reward; after turning over the key and receiving the reward, he dies abruptly.
Following the death and funeral of Tywin Lannister, Cersei's reign is marked by rampant cronyism, and her councils staffed with incompetent loyalists. She also disregards accurate advice by her uncle Kevan Lannister and her brother Jaime, alienating them both. Making matters worse is Cersei's increasing distrust of the Tyrells, particularly Margaery, whom Cersei implicates in a prophecy that Cersei herself will see her children crowned but all of them will die before her.
Her incompetent management raises the kingdom's debts to the Iron Bank of Braavos and the Faith of the Seven. When Cersei dismisses its representatives, the Iron Bank refuses to grant new loans and demands immediate repayment, nearly crippling the economy of Westeros. To settle the crown's debts to the Faith of the Seven, Cersei permits the restoration of that religion's military order, the Faith Militant, ignoring the danger to her own power. Hoping to weaken the Tyrells, Cersei dispatches Ser Loras Tyrell to besiege Stannis Baratheon's forces on Dragonstone; as a result, almost a thousand loyalists are killed, and Ser Loras is gravely injured. A scheme to falsely have the Faith put Margaery on trial for adultery backfires when the religious leadership imprisons Cersei herself on similar (correct) charges.
After a series of disagreements, Cersei dispatches Jaime to the Riverlands to re-establish control. He negotiates with Brynden "the Blackfish" Tully to surrender Riverrun in exchange for Edmure Tully's life. Though the siege ends bloodlessly, Brynden escapes, to Jaime's fury. He then receives word that Cersei, who has been imprisoned, wants him to defend her in a trial by combat; but learns that Tyrion's accusation of Lancel Lannister and Cersei was true (Lancel having been King Robert's true killer). Disgusted by the excessive loss of life and Cersei's paranoia, Jaime abandons her to her fate.
Brienne of Tarth's quest for Sansa leads her all over the Riverlands, where she observes the destruction caused by the war, and acquires Podrick Payne, former squire to Tyrion Lannister. She meets Ser Hyle, a knight whom she has met before, and Lord Randyll Tarly (Samwell's father), who insults her despite Ser Hyle's praise of her. Eventually she is captured by the Brotherhood Without Banners and sentenced to death by Catelyn Stark, who was resurrected three days after death by Beric Dondarrion, though at the cost of Dondarrion's life, and who has now assumed the name Lady Stoneheart. Catelyn offers to let her live if she agrees to kill Jaime Lannister (whom she believes played a role in Robb's death). When Brienne refuses to decide, she and some of her companions are sentenced to be hanged, at which she screams an undisclosed word. The author later revealed that the word was "sword", in response to Catelyn's ultimatum of "Sword or noose", which offered either Brienne's continued service to Catelyn herself, or hanging.
In the Eyrie, Sansa poses as Petyr's daughter Alayne: befriending young Robert Arryn, managing the household, and receiving informal training in royal politics. During this time, Petyr appears to be carefully manipulating his murdered wife's former bannermen and securing control of the Protectorship of the Vale. He eventually reveals that he has betrothed Sansa to Harrold Hardyng, the next in line to Robert's title; when the sickly Robert dies, Petyr intends to reveal Sansa's identity and claim her family stronghold of Winterfell in her name.
On the Iron Islands, Aeron Damphair calls a Kingsmoot to identify Balon Greyjoy's successor as king of the Iron Islands. Hotly contested by Balon's brother Victarion Greyjoy and daughter Asha Greyjoy, eventually his brother Euron Greyjoy is chosen as king for his promise to control dragons with an enchanted horn he possesses. The fleet of the Iron Men captures the Shield Islands at the mouth of the river Mander, threatening House Tyrell's seat at Highgarden. Victarion estimates that when the Redwyne fleet returns from the siege at Dragonstone it will retake the islands; and when Euron sends him east to woo Daenerys Targaryen on his behalf, to thus gain a claim to the Iron Throne, Victarion decides to woo her for himself instead.
In Dorne, Doran Martell is confronted by three of his brother Oberyn's daughters, who want vengeance for their father's death. Because they are inciting the commonfolk, Doran has them imprisoned in the palace.
A bold attempt by Doran's daughter Arianne Martell and her lover, Ser Arys Oakheart of the Kingsguard, to crown Doran's ward Myrcella Baratheon as queen of Westeros under Dornish law, is thwarted by Doran. In the confusion, one of Arianne's co-conspirators, the knight Gerold "Darkstar" Dayne, attempts to kill Myrcella; she survives but her face is scarred, and Ser Arys is killed. This strains the new Dornish alliance with House Lannister and the Iron Throne. To his daughter, Doran reveals that her brother Quentyn has gone east to bring back "Fire and Blood".
Arriving in Braavos, Arya Stark finds her way to the House of Black and White, a temple associated with the assassins known as the Faceless Men. As a novice there, Arya attempts to master their belief that Faceless Men have no true identity by throwing all her treasures into the water (secretly keeping her sword, Needle) and posing as a girl called "Cat of the Canals". Her former identity asserts itself in the form of wolf dreams, and also when she kills Dareon, sworn brother of Samwell Tarly, for abandoning the Night's Watch. Having confessed this death, she is given a glass of warm milk as punishment. She wakes up the following morning blind.
Jon Snow has ordered Samwell Tarly to sail to the Citadel in Oldtown (via Braavos), to research the Others and become a Maester. Sam is accompanied by aging Maester Aemon, the wildling mother Gilly, her newborn baby, and sworn brother Dareon. The voyage across the Narrow Sea is underway before Sam realizes Jon swapped the sons of Gilly and Mance Rayder, to protect the Wildling "prince" from sacrifice by the priestess Melisandre. Aemon becomes sick and the party wait in Braavos for his health to improve. After a Summer Islander tells Aemon about the Targaryen dragons, Aemon decides that Daenerys has come to fulfill a prophecy. He dies shortly after they leave Braavos.
At the end of the novel, Samwell arrives at the Citadel to begin his training. He meets a fellow apprentice who introduces himself as Pate, connecting the prologue to the narrative.