In my review for the previous episode, I noted how all the characters were on the "fringe" of normality, and how that was the defining aspect of the series. For all that it's become pigeon-holed as nothing more than an "X-Files" knockoff, it has focused on tighter continuity for both plot and character than its forebear ever did.
This episode, for example, accomplishes two very important tasks. We know why Agent Dunham is involved with Agent Broyles' secret task force, and we know that Walter Bishop is a lunatic who relishes the chance to play with his toys again. But what compels Peter Bishop to remain? It's a question that has been lingering since the pilot, and this episode provides an answer.
Peter's motivation is now rather simple. He's had an Experience, and he wants to understand it. That desire for closure was only deepened after his conversation with his father at the end of the episode, when it became clear that this latest moment of weirdness was only the most recent. Walter is still holding back, of course, and Peter can't possibly guess how much his father has likely messed with him over the years, but now he's driven towards the truth.
This is good, because up until now, Peter has been around to toss out sarcastic commentary and make occasional eyes at Agent Dunham. Since Dunham is still reeling from the loss of Agent Scott, any Olivia/Peter relationship would be out of character. Considering that the writers appear to be going for a season arc approach, these early episodes are all about introducing the characters and their individual psychological underpinnings. It would have been easy to ignore Peter, so this much attention is a comforting sign.
The second task relates to the mythology of the series, which complicates in this episode, but in a good way. The Observer is creepy, and while he is a familiar kind of figure in the genre, it is still intriguing. It expands the playing field more than expected. Instead of having just the complex interplay between law enforcement, Massive Dynamic, and the terrorists involved with the Pattern, there's Someone Else that has been keeping an eye on things for decades. And that Someone Else hasn't aged and may see an even deeper Pattern driving the one that caught Broyles' attention.
That said, this episode was a bit more obscure than the previous installments, and I'm not sure that it will be well-received. One criticism that has been voiced often is the inaccessibility of Agent Dunham's character, and I'm beginning to see the validity of that point. It makes sense for Dunham to be dour and morose, given her recent experiences, but it's closing off the audience as well. So far, Walter is still providing enough wacky fun to compensate, but the growing darkness of his instability needs to be offset by more than Peter's sarcastic wit.