This week was a chip in the brain to fix sleep disorders that allows people access to the brain / dreams of those with the implant. First, they think it's an attempt at mind-control, but when Walter experiments on the brain of Agent Zachary Ty Bryant, he realized that it's like all the craziest drugs all at once, everything that goes through the other person's mid-brain poured into yours-- and the culprit is an addict of the rush that causes. But the result is that those he feeds off are living their dreams and killing people. This week's ick: several shots of slimy brain surgery, and pulling things out of said brains.
But the background of the show was shifting around while all this was happening. Olivia's dealing with Charlie's death and whether or not it's her fault and the creepiness of finding out that he was dead ages before she knew it (though they haven't really mentioned that part...). Peter is remembering that he used to have horrible night terrors when he was a kid, and now that he remembers, he starts having the dreams again. They apparently involve talking in his sleep, and what he's saying freaks Walter out. Meanwhile, Astrid is continuing to be adorably fond of Walter, and he's responding well. I like watching that weird little friendship happen.
I think Peter is remembering his own snatching. And I think that's going to be the arc of this season-- getting around to Peter's realization that he's not who he thinks he is, and therefore, everything he thinks about his life isn't right. The trust between him and Walter is only barely starting to solidify, and it'll be shattered. Maybe they'll even set it up so Other Walter shows up, and then he'll have to choose sides in the Coming War. Maybe he'll choose the other side and wind up facing off with Olivia, which I think would be horrifying, unless the result is to bond them closer as a team so they can work together to save both universes. There's so much potential for crazy pathos there.
The show is less about Olivia these days. She's sort of out of the equation by being messed up and frequently off doing something she isn't sharing with the others, and Peter finally having a purpose means he's doing a lot of the work these days. I'm not comfortable with the shift away from Olivia being a strong, empowered woman with a tech-savvy genius behind her left shoulder, but I'm willing to let them find a new equilibrium.
Otherwise, the episode was kind of slow...