It's almost a requirement, as the season ends we need to get back to that series arc that turn Patrick Jane, otherwise light and funny, into a dark and dangerous character. Because as he said before, and I'm sure he means 100%, when given the chance, once he'll find Red John, there won't be no such thing as the law and bringing him to justice, all that will matters is revenge, and making sure he pays for what he did.
But of course, that is only for in a few years when the series will end, and until that we have a long road ahead of us, made of little (or not so little) clues as we did get with this episode. A new murder to investigate, and one that will be linked to the infamous serial killer of course, but one very unlike all his other crimes, in more than one way.
With this one, we got much closer to home, finding out that Red John wasn't working alone after all, and then there was the blind girl. Okay, we'll come back to this later, but first the accomplice. I have to say that I didn't see the "twist" about his identity coming as soon as I'm sure some of you will have, but in retrospect I should have. Even though to better fool us they addressed Jane earlier on Jane's ways when it came to this case, the fight between him and Lisbon was quite out of character for her, almost sounding a bit forced.