I really liked it for the way how so many storylines converged at the brothel and how that was a tragic case of bad timing for some (Gillian in particular) and good timing for others (Richard who might not have survived his assault on the house if Massaria's people had still been around). I was surprised that Nucky's plan was much more elaborate than I would have thought (also playing Rothstein).
The scene between Nucky and Margaret was quite tense and interesting. I guess she got her period and wasn't actually pregnant after all? Or did she have an abortion? She was really scared of Nucky in the beginning and I'm not sure what will happen between the two of them next season. Nucky seems to be quite unhappy with his fate, too.
Rosetti's end was awesome and quite fitting regarding his craziness. For a moment, I thought the writers would let him get away to California or something.