In "Garden of Bones," Season 2, episode 4 of Game of Thrones, several key events take place that further the overall plot of the series.
In King's Landing, Tyrion Lannister, the Hand of the King, continues to implement his own policies and strategies to maintain control of the city and the realm. He also starts to gather information about his enemies and allies. He also tries to improve the living conditions of the people of King's Landing by setting up a brothel for the pleasure of the soldiers and smallfolk.
In the North, Theon Greyjoy continues to struggle to gain the support of his father and his people in his attempt to conquer the North. He captures Winterfell, but his lack of support and leadership skills lead to a lack of provisions, desertions and ultimately a siege.
In the Riverlands, Robb Stark's army is continuing its campaign against the Lannisters. Robb receives a letter from his mother, Catelyn Stark, who urges him to make peace with the Lannisters and exchange Jaime Lannister, who is being held prisoner, for Eddard Stark, who has been executed by the Lannisters. Robb decides to continue his campaign and capture Harrenhal, a strategic location.
In the East, Daenerys Targaryen is building her army and her dragons are growing bigger. She also starts to learn more about the culture and customs of the people she is trying to lead. She is also captured by a group of warlords who want to use her as a bargaining chip.
In the Night's Watch, Jon Snow and his comrades are preparing for the wildlings' attack on the Craster's Keep. Jon is also struggling with his loyalty to the Night's Watch and his feelings for Ygritte, a wildling woman he had met earlier.
In summary, "Garden of Bones" continues to establish the power struggles and secrets that drive much of the series. It also sets up several key conflicts and alliances that will play out in later episodes. The episode also showcases the brutal nature of the world of Game of Thrones, with the Theon's struggle to maintain control of Winterfell and Daenerys' capture serving as a reminder of the high stakes and ruthless tactics used by those vying for power.