On a positive note, how freaking good was Cersei's acting in the last episode? Honestly she's my favorite character in the entire show. I think my single favorite thing about episode 4 was how she used her facial expressions and said so much without saying anything.
When they strolled up to King's Landing, honestly, that whole scene gives me chills. It feels like walking up to a final boss in an RPG that you know is menacing, powerful, and ruthless. Qyburn as the master of black magic, Ser Gregor as the undead warrior bodyguard, the pinnacle of physical might, and Cersei, the despicable, cruel, tyrant queen. Qyburn hasn't really had a lot of screen time or important moments, but boy does he feel deadly. I love the brief pensive moment he has when he responds to Tyrion's comment about screams of burning children. So evil in such a subtle way.