A Night's Watch deserter is tracked down outside of Winterfell, prompting swift justice by Lord Eddard "Ned" Stark and raising concerns about the dangers in the lawless lands north of the Wall. Returning home, Ned learns from his wife Catelyn that his mentor, Jon Arryn, has died in the Westeros capital of King's Landing, and that King Robert is on his way north to offer Ned Arryn's position as the King's Hand. Meanwhile, across the NarrowSeain Pentos, Viserys Targaryen hatches a plan to win back the throne, which entails forging an allegiance with the nomadic Dothraki warriors by giving its leader, Khal Drogo, his lovely sister Daenerys' hand in marriage. Robert arrives at Winterfell with his wife, Queen Cersei, and other members of the Lannister family: her twin brother Jaime, dwarf brother Tyrion and Cersei's son and heir to the throne, 12-year-old Joffrey. Unable to refuse his old friend and king, Ned prepares to leave for King's Landing, as Jon Snow decides to travel north to Castle Black to join the Night's Watch, accompanied by a curious Tyrion. But a startling act of treachery directed at young Bran may postpone their departures.

Bran's fate remains in doubt. Having agreed to become the King's Hand, Ned leaves Westeros with daughters Sansa and Arya, while Catelyn stays behind to tend to Bran. Jon Snow heads north to join the brotherhood of the Night's Watch. Tyrion decides to forego the trip south with his family, instead joining Jon in the entourage heading to the Wall. Viserys bides his time in hopes of winning back the throne, while Daenerys focuses her attention on learning how to please her new husband, Drogo.

Arriving at King's Landing after his long journey, Ned is shocked to learn of the Crown's profligacy from his new advisors. At Castle Black, Jon Snow impresses Tyrion at the expense of greener recruits. Suspicious that the Lannisters had a hand in Bran's fall, Catelyn covertly follows her husband to King's Landing, where she is intercepted by Petyr Baelish, aka "Littlefinger", a shrewd longtime ally and brothel owner. Cersei and Jaime ponder the implications of Bran's recovery; Arya studies swordsmanship. On the road to Vaes Dothrak, Daenerys finds herself at odds with Viserys.

Ned looks to a book for clues to the passing of his predecessor, and uncovers one of King Robert's bastards. Robert and his guests witness a tournament honoring Ned. Jon takes measures to protect Samwell from further abuse at Castle Black; a frustrated Viserys clashes with Daenerys in Vaes Dothrak; Sansa imagines her future as a queen, while Arya envisions a far different future. Catelyn rallies her husband's allies to make a point, while Tyrion finds himself caught in the wrong place at the wrong time.

Incensed over news of Daenerys' alliance with the Dothrakis, Robert orders a preemptive strike on the Targaryens that drives a wedge in his relationship with Ned. A captive Tyrion helps Catelyn, but receives a cold reception at the Eyrie from her sister, Jon Arryn's widow Lysa. Sansa is charmed by the dashing Ser Loras Tyrell, a.k.a. the Knight of Flowers. Arya overhears a plot against her father.

Reinstated as the Hand, Ned sits for the King while Robert is on a hunt, and issues a decree that could have long-term consequences throughout the Seven Kingdoms. At the Eyrie, Tyrion confesses to his "crimes", and demands that Lysa give him a trial by combat. Joffrey apologizes to Sansa; Viserys receives his final payment for Daenerys from Drogo.

Explaining that the future of the Lannisters is at stake, Tywin presses Jaime to "be the man you were meant to be" as they prepare for battle. Ned confronts Cersei about the secrets thathuged Jon Arryn. With the fate of the missing Benjen very much on his mind, Jon Snow takes his Night's Watch vows, though not with the assignment he coveted. After Ser Jorah saves Daenerys from treachery, an enraged Drogo vows to lead the Dothraki where they've never gone before. An injured Robert takes pains to ensure an orderly transition at King's Landing.

In the aftermath of Ned's capture, Syrio and Arya face off against Lannister guards, while Cersei manipulates Sansa to her own ends. Robb rallies his father's northern allies against Tywin Lannister and heads south to war. Tyrion forms an uneasy alliance with the hill tribes and reunites with his father. Jon lashes out at Ser Alliser Thorne and battles a mysterious attacker from beyond the Wall. Dany is forced to reconcile her desire to conquer Westeros with Drogo's savagery after the Dothraki raid a peaceful village.

With Sansa's life in danger, Ned makes a fateful decision. Catelyn brokers an unsavory deal with the slippery Walder Frey. Tyrion acquires a mistress and is forced by his father to fight on the front lines. Robb wins his first major victory and captures a prized prisoner. Jon is rewarded for his valor and discovers a dark secret about Maester Aemon. As Drogo... s wound festers, Dany defies her bloodrider Qotho and puts her trust in the enslaved witch Mirri Maz Duur.

As tragic news spreads across the Seven Kingdoms, Bran and Rickon share a prophetic dream, Catelyn interrogates Jaime about her son... s fall, and Robb... s destiny is forever changed. After a surprising decision by his father, Tyrion heads south. Arya assumes a new identity in an attempt to escape King... s Landing, and Sansa is terrorized by Joffrey. At the Wall, Jon is forced to choose between the Night... s Watch and the family he left behind. Across the sea, Dany pays a terrible price for her love, but finds new hope.