3x1: Valar Dohaeris
Jon meets Mance Rayder, the king of the "savages", and he will decide if his place is among the Night's Watch men or if he drops out the black cloak. Meanwhile, in King's Landing, Tyrions asks for his reward, as Sansa plans a possible way out from his situation.
Valar Dohaeris is the first episode of the third season of Game of Thrones. Just to recap, remember that last scene from season 2 showed the White Walkers heading the Wall. Winter is closer is closer and with it this major threat.
First of all, Jon Snow is now with the wildlings and he's introduced to Mance Rayder, the King beyond the Wall. A giant appears in this area and lives with the rest of women and children of the camp. Jon is now decided to fight against the walkers, no matter he's with the people of the Seven Kingdoms or those beyond the wall.
Back in the Seven Kingdoms, House Tyrell and the Lannisters are now allies. Tywin looks down his son Tyrion and doesn't recognize his effort at all. Lady Margaery tries to improve her position by getting closer to the people needs and issues. Cersei doesn't trust Margaery at all at tries to strengthen the bond with her son Joffrey.
Interesting facts: did you know that Valar Dohaeris is what people from Braavos answer to Valar Morghulis? It actually means "All men must serve". Some of Arya's scenes were originally shot for this episode but they were finally included in the next one.