"Subject 9" was an episode of Fringe so filled with memorable scenes that it's hard to pick a favorite or select some that matter more than the rest. Even more than previous episodes of this new beginning, it helped the audience to understand the lead characters and seemed to do so beyond the new timeline, somehow, also filling in the blanks we had after three seasons of the show. Maybe because of this, although it was a surprise, the fact that the episode brought back a major character (Peter) feels like a natural development, the story having reached a point from which it can really spring forward.
It was fitting that the episode featuring the return of Peter was centered on the two people to whom he matters (or should matter) the most, Olivia and Walter. Things seem at first to start from where we left off last week with an energy "field" forming in Olivia's bedroom and with Walter trying to design a way to capture images of the ethereal man haunting him and appearing in Olivia's dreams. That is until the story (or more precisely, Walter) didn't make the obvious connection we the viewers could make because we knew the nature of the "ghost."
The story then led us on a different path with Walter and Olivia embarking on a quest for the Cortexiphan test subject who was, according to Walter, in all likelihood behind the astral-projections. The Cortexiphan trial is a difficult subject for Fringe as it always brings up the despicable practice of experiments on children and invariably affects Olivia's disposition toward Walter. To make matters worst in this timeline, it turns out Olivia remembers everything from her childhood and, to further complicate things in this episode, it just so happened that her recommendation (following the previous episode's assessment by St. Clair's Dr. Summer) was to determine whether Walter would return to the mental institution or not.
Having laid out their pieces, the writers proceeded mercilessly. Walter, who is much less grounded since the beginning of the season, struggled with his past actions and went as far as stopping the TV set connecting him to the outside world (via Astrid's nifty camera) to avoid her conversation with Olivia on the Cortexiphan trial. His guilt plagued him throughout the episode, especially when they met Mark Little, subject 9, who kept reminding Walter the extent of his fault.
After her conversation with Astrid on the trial, Olivia was even less patient with Walter than she's been since the beginning of the season, which was already much worse than what we had been used to. The episode showed it very well before bringing us to realize that he needed her help, and each time, it seemed she realized it as well and collected herself to calm him. It happened after his panic attack (because of nosophobia) in the hotel room and again when she needed him to find a way to save them from the mysterious force.
We also had some insights into a couple of other relationships. It appears Nina Sharp and Walter do not see eye to eye in this timeline. His words to Nina were clearly insulting and Astrid's peacemaker rewording couldn't make Nina believe Walter could be nice to her. That scene, made possible by the communication device through Astrid, showed him much nastier than he has ever been before and was excellently portrayed by John Noble. It is also apparent that Olivia and Nina have known each other since at least high school, and known each other well enough for the former to confide in the latter on high school prom emotional distress. These facts are interesting because on the one hand, Walter clearly doesn't trust Nina (and who could blame him?), but on the other hand, there is a close relationship between Olivia and Nina, even though Olivia did hold back a few things. Anna Torv also delivered an impressive performance. Olivia moved from being her new buttoned-up self (much like she was at the beginning of the series) to being sweetly coy with Nina Sharp, then clearly irritated with Walter before easing off toward the end.
The depiction of Nina, Walter and Olivia during this episode made more obvious a particular fact about the characters in this timeline. They are all recognizable, but some specific aspects of their personalities are stronger than they were in the previous seasons, both in the way the characters are being portrayed and in the way the story is depicting them. Nina's unequivocal statement about Massive Dynamic providing technology — and not caring about how it is used — is a perfect example of the writers blatantly showing something that was only hinted at previously, and it also shows Nina and Massive Dynamic without the traces of the scruples and humanity visible in the previous seasons. Also, the Fringe division seems more powerful: it is still a small shop compared to what they have on The Other Side, but there is the fact that Broyles's boss is Blanket Authority...
Walter leaving the lab allowed Olivia to be a bit more objective on her recommendation. They might not be family and she might still harbor some grudge against him because of the Cortexiphan trial, but they clearly need each other. The trip outside also gave the first Walter moment with a female (beside memories of Elisabeth) in three years; something clearly passed between Mark Little's landlady and the good doctor. When the story pivoted away from subject 9 as the force behind the "distortions of the magnetic field," it became clear to the viewer that Peter was back as the most probable cause. This led us to what was maybe both the strongest and weakest moment of the episode.
Peter trying to crossover from wherever he was to our "dimension" was excellent, just like Olivia's irrational decision to stop Mark. What I found wanting was how easily Mark could do whatever it is that he was doing. In the world of superpowers, there are unwritten rules. I know time was short, but one does not move from being totally overpowered by some ability to perfectly controlling it at such a scale in the blink of an eye. We either get a fully functional superpowered being from the start or we get to see some training!
It was fitting for Peter to appear at Reiden Lake, though his physical existence in this timeline will need a lot of explaining to sit well with me. Then again, each time I was uneasy about an event last season the writers pulled it off, so I am hopeful. Finally, given how much information he had on the division (information probably including his own name, Peter Bishop), Broyles could have seen him before the team got there, or they could have met him together. But of course, none of that would have been as dramatic as having "our" Olivia facing him alone in a room, intently looking at this man she knows without knowing and asking him, to his surprise, who he is.