S4E4 · Oathkeeper

Complete story — includes the ending

Daenerys easily captures Meereen, instigating a slave revolt. Seeking justice for 163 slain slave children, she nails 163 masters to the same road posts. At sea, Littlefinger tells Sansa that he had plotted Joffrey's murder with the Tyrells and that it was Olenna who had administered the poison to protect her granddaughter. Before leaving King's Landing, Olenna reveals her guilt to Margaery and urges her to seduce Tommen, who will be a much kinder and more pliable husband. Jaime believes Tyrion is innocent, but Cersei is adamant he is guilty and also orders Jaime to locate and kill Sansa, whom she believes was an accomplice. Jaime instead sends Brienne to find and protect Sansa, presenting her with new armor, his Valyrian Steel sword, which she names Oathkeeper, horses and Podrick Payne as her squire. In the North, hoping to eliminate Jon, Alliser Thorne and Janos Slynt agree to allow Jon to lead the expedition against the mutineers. Unknown to Jon, the mutineers have captured Bran and his companions. Further north, a White Walker takes Craster's last newborn son to a secret ritual site where he is transformed into a Walker by the Night King.