Okay, so now that we are all caught up, I will assume that everyone reading this review knows about the two universes that were basically tearing themselves apart. You should also know that it's all because Walter (John Noble) lost his son and, in an attempt to save the parallel universe's version of Peter, crossed over and took him back to our world. Upon returning, Peter and Walter fell into a frozen lake and almost died. The only thing that saved them was an Observer who did more than just watch the events play out.
Well, by completing and activating The Machine, Peter not only linked the two universes to start them healing, but he "fixed" the timeline so that the Observer named September (Michael Cerveris) never saved Peter. As a result, while Walter is helping Fringe Division, he never leaves his lab and Astrid (Jasika Nicole) is his eyes and ears on cases. Olivia (Anna Torv) feels a lot like the Olivia from the show's start, a loner who is overly focused on her job.
There are other differences as well; people who died in the first three seasons of the show might still be alive and relationships that seemed firmly established before are now turned on their ear. Just when you get a good grasp on how the characters have changed, a monkey wrench gets thrown in the works and Peter somehow breaks back into the new timeline. Now he has to somehow convince everyone of who he is and try and figure out how to either find a place for himself or get to a timeline that he fits in.
I mentioned above that some characters previously dead would be back, well, among them is Agent Lincoln Lee (Seth Gabel) who joins Fringe Division after his partner is killed. Another is one of the season's, and the series', main villains, David Robert Jones (Jared Harris). Since Peter was the one that finally took down the dimension-crossing enemy in the past, it should be no surprise that he is still around this time around as well.
Oddly enough, while the series as a whole has focused a lot on the two dimensions, with that crisis mostly resolved, we begin to see a new threat on the horizon. We learn a lot more about the Observers, including who they are, but we might not like what we learn. While Season Four might resolve pretty much every issue and answer most of the questions posed in the rest of the show, it once again leaves the viewer with a pretty big cliffhanger.
Fringe: The Complete Fourth Season has a lot of special features that any fan of the show will want to watch. The featurettes include one on how the world is different without Peter, and one going into detail about The Observers. There is also a featurette on the comic mini-series that Jackson wrote featuring Peter's journey while he was outside of time, as well as an excerpt from the same comic. The last few special features include a round-table discussion about the the cultural and social impact of the show, as well as the standard gag reel and a series of clips featuring some of Walter's most abnormal statements.
If you follow the show at all, then you will want to see where it goes. On the one hand, the premise of the entire season feels like the show is taking one more step away from normal, but then again, it doesn't feel like any bigger step than the ones it took before. In an odd sense, this feels like another natural step in the same direction it was always supposed to go. Although, I have to say that the next step the show takes by the end of this season seems to take Fringe in a very different direction. I am curious to see where it goes from here.