Game of Thrones - Season 6, Episode 4 Synopsis
 

Episode 6 - 4
Title: "Book of the Stranger"
Directed by Daniel Sackheim
Written by David Benioff & D. B. Weiss
Original Air Date - May 15, 2016

Sansa's party arrives at Castle Black as she is reunited with Jon. In Meereen, Tyrion meets with the slave masters of Slaver's Bay to offer peace if they will end slavery within a period of seven years, an action that angers the former slaves. Baelish returns to the Vale to mobilize their soldiers against Ramsay. Naharis learns about Mormont's greyscale as they arrive in Vaes Dothrak. In King's Landing, Margaery is permitted to visit Loras while Cersei, Jaime, Kevan and Olenna put aside their differences and plan a defeat of the Sparrows. Theon arrives at Pyke and explains to Yara that he will support her claim at the Kingsmoot. In Winterfell, Osha attempts to assassinate Ramsay but is killed by him. Ramsay sends a letter to Jon, threatening harm to Rickon if Sansa is not returned. She convinces Jon to march south in order to take back Winterfell. Daenerys meets with the Khals in the temple of the Dosh Khaleen; after they refuse to serve her, she burns them and Moro to death. When she emerges unhurt, the Dothraki kneel to her.

Source: https://en.wikipedia.org/wiki/Game_of_Thrones_(season_6)