Finally Stannis arrives to King's Landing! Baratheons and Lannisters engage in combat. No more spoilers!
We're definitely sure that Blackwater is one of the best episodes from the entire series. This chapter features the massive attack from Stannis Baratheon to King's Landing.
As we've seen in the previous episodes, Stannis fleet is extremely large, so it seems there's no way for Joffrey to deal with that amount of men. However, a brillant idea appeared in the last episodes and it is finally executed by Tyrion Lannister.
Insted of directly attacking Stannis ships with his own fleet, Tyrion decides to use Wildfire (an extremely flammable liquid) to make a huge part of the fleet explode. The strategy works perfectly and the people defending the throne must only deal with soldiers. In conclusion, the throne remains in the Lannister family and Stannis manages to escape.
Interesting facts: the episode is titled Blackwater as it shows The Battle of the Blackwater. Did you now that George R. R. Martin (the writer of the books) wrote this episode? The first one written by him was "The Pointy End" from season 1.