The episode titled The Lion And The Rose.
MAJOR SPOILAGE ALERT: Do not read below the orange turd if you have not seen this episode and will watch it later.
Again... spoiler alert spoiler alert... you have been warned.
Early on in this episode how many viewers (who haven't read the books) thought the royal blood to be spilled would be from Theon Greyjoy slicing Ramsay Snows throat from ear to ear while giving him a shave? "Reek" may seem to be completely cowed, but he is obviously fighting some inner demons that one imagines could manifest in a violence filled glorious ending to Theons torment.
But... of course the episodes conclusion, (the murder of King Joffrey by poison) came as a bolt from the blue. In so far as bolts from the blue can be greeted by exclamations of "YES!!" with smiles and fist pumps of exultation. The producers masterfully brought out Joffrey's total dickishness just prior to his death with his tormenting of his 'imp' uncle Tyrion, who finds himself in the difficult position of being accused of poisoning his asshole nephew and (evidently) being hauled to gaol on the orders of Cersei. I suppose Tyrion is lucky to not have been put to the sword on the spot, but perhaps he would actually have been better off with that fate than what he faces going forward. Unless his father can pull some strings, and perhaps banish him to join his girlfriend across the sea... But who am I to speculate? Just based upon this episode and several others with bolt from the blue plot twists, my speculation is not worth a bucket of warm spit.
If Tyrion does not survive he will be missed, but I for one am prepared for his passing from GOT. What else should we expect at this point? Further it must be said that even though Joffrey will not be missed, our over the top reaction to his passing is a testament to the fantastic portrayal of the character by Jack Gleeson, who seems to be a pretty up front and cool dude in real life.
It is obvious that the knight who Sansa saved from death by drowning in wine, who was then made to be the kings fool had a hand in Joffreys death. But I for one do not think he acted alone and the list of those who must have had the same reaction as the rest of us when Joffrey started puking and turned all purple and bloody is very long indeed. The kings fool is involved but his attempt to spirit Sansa from the scene would implicate them both, and it is hard to imagine them escaping from the very center of the Lannister empire unless the fool has a very well laid plan for the occasion.