I know I am late to the party, but it looks like nothing much happened anyway.
Not too much happened with Brian in this episode. The only thing that happened was something that we were all expecting anyway. We all knew that Brian would go to his old ways and take charge of everything. He even went as far as recreating his aquarium wall of heads. It is just this time he is putting his walkers into the lake.
The Governor is very good at what he does. He told Martinez that he did not want the crown. That he was done with his old ways, that he is a changed man. This is when things turned for the worse. Brian smacked Martinez in the back of the head with the golf club (I thought golfing was supposed to be relaxing). When he hit him in the head, he then took Martinez into the walker pit. After he killed him this started a chain reaction making Brian kill Pete. By doing this Brian is now the leader of this group.
I just wonder if everyone else will find out what happened. If not, then I wonder if they will see Brian for who he truly is when they go and attack Rick and the group.