Now at last we know why Peter and Olivia are important on FringeS

Fringe has been teasing us for ages with hints that Peter Bishop and Olivia Dunham are super important — and that their romance could have universe-shattering (or saving) consequences. Now, with last night's episode, we finally get to see the reason why these two lovebirds matter so doggone much.

Spoilers ahead...

Last night's Fringe episode introduced us, at last, to the spawn that Peter and Olivia were supposed to have, Henrietta "Etta" Bishop. (And yes, it's awesome that Etta hands out candy.)

Now at last we know why Peter and Olivia are important on FringeS

You might recall that not too long ago, September told Peter that he'd made a baby with the "wrong" Olivia in the timeline that was erased — Henry, born on the Other Side. When that timeline was wiped out, Peter was erased along with his newborn son. And most of the Observers seemed extremely keen to keep Peter from being restored to the timeline — except for September, who rebelled against his crew to help restore Peter to the universe. And September basically told Peter that the reason it was important for him to exist was so that he and Olivia would make a very special baby.

September also told Olivia that she would have to die — and now we know when. She dies roughly in 2016, when Etta is four years old.

Now at last we know why Peter and Olivia are important on FringeS

So what does Etta do that makes her so important to September? It seems likely that she's a direct threat to the other Observers, and that's what made them so keen to have Peter stay erased, back at the start of this season. All we know, for now, is that she is instrumental in rescuing Peter, Walter and Astrid from amber in 2036. And that she has some kind of weird mental power that makes it impossible for Observers to read her mind. A side effect of being the daughter of a Cortexiphan kid? (I'm not advocating Lamarckian genetics here, just saying that the Cortexiphan may have tweaked Olivia's genes somehow, or may have had some influence on Henrietta in the womb. Plus we still don't know what William Bell did to Olivia.)

Now at last we know why Peter and Olivia are important on FringeS

So was the future we saw in "Letters of Transit" one possible future, or THE future? I'm inclined to say the latter. Of course, September has told Walter before that the future is always in flux, and he sees many possible futures coming in and out of likelihood — but think about how the show treated the future the last time we visited it, in "The Day We Died," the third season finale. There, it seemed like the dystopian 2026 that Peter visited was what would happen, unless Peter made a change in 2011. Peter sent his consciousness back in time so that his past self in 2011 could make a different choice — and that dark version of 2026 was averted. In "Letters of Transit," there's no communication with the past, and thus I think we're left to assume that this is what will happen, if nothing is done to change the timeline. Again.

Now at last we know why Peter and Olivia are important on FringeS

Plus, if this was just one possible future, then what was the point of it? Our heroes in 2012 don't know about this version of 2036, so there's no way for them to try and avert these events. September presumably saw this future and deliberately didn't warn them — instead, he influenced events so that Peter and Olivia would get together and create the (presumptive) savior Henrietta. (Plus given the amount of time this episode spends introducing her character, you can bet the adult Henrietta will reappear in season five, if there is one. When Georgina Haig was first cast, her role was described as "potentially recurring" next season.)

Now at last we know why Peter and Olivia are important on FringeS

In any case, here's what we know about the timeline we glimpsed last night. Sometime in 2012, Peter and Olivia make a baby, Henrietta. And then in 2015, a ton of Observers show up from the future — way more than can be covered by "months of the year" names — and they take over the planet. At some point during that year, soldiers (Native ones, I guess) go door to door, pulling suspected Resistance members out of their homes and shooting them. By 2016, the Observers' grip is tight — although the Fringe team keeps fighting them. Eventually, the Fringe team gets cornered, and Walter puts himself, Astrid, Peter and William Bell into amber so they'll be hidden from the Observers.

Now at last we know why Peter and Olivia are important on FringeS

By 2036, the world is a full-on dystopia, and the Observers have become your standard evil overlords, oppressing the "Natives" of the 21st century. Whether the Observers traveled back in time to avert the ecological disaster that makes the world uninhabitable in 2609 or just to gain a new dominion to rule over, they've gotten totally corrupted. They even go into speakeasy-style nightclubs and demand the hottest women for themselves, because apparently Observers have needs too. Manhattan, referred to as "The City," is pretty much exclusively their domain.

Now at last we know why Peter and Olivia are important on FringeS

And the Observer overlords have a slew of human lackeys, who have symbols tattooed on their faces, and the once-defiant Fringe Division now polices human-on-human crime for them. Broyles, in particular, seems to have become a willing collaborator with the occupation, and has a very Casablanca-style relationship with the Observer known as Widmark, who swigs water as though it was... well, water. (Although he doesn't seem in a hurry to tell anybody when he finds one of Walter's trademark Red Vines at the end of the episode.)

Widmark makes a notably creepy villain, especially the way he threatens to take over policing Native crime with methods that Broyles wouldn't like. And the way he explains his current "crap detail" by smiling and saying "I like animals."

Now at last we know why Peter and Olivia are important on FringeS

But luckily, a couple of Fringe agents are still secretly working with the Resistance. There's Simon (Lost's Henry Ian Cusick) whose parents were killed for being Resistance members, back in 2015. And Etta, who seems reluctant to tell Simon why she's so attached to Walter and Peter Bishop. One of Etta's contacts has found the Fringe team in amber, and managed to pull Walter's piece of it out, before being killed. So all Etta and Simon have to do is figure out how to get Walter out of amber that re-solidifies the moment it's dissolved, and then enlist the aid of a ridiculously wigged Nina Sharp to restore Walter's amber-addled brain.

Oh, and back in 2015 Walter designed some new crazy device, which will supposedly rid the world of the Observers once and for all.

So what happened to Olivia? How did she die? It could have something to do with the spent bullet casing that Henrietta wears around her neck, which she instinctively touches when she first sees Walter in amber. Also, I'm guessing that whatever William Bell did to Olivia that made Walter so mad, it's somehow connected to his mind-possessing "soul magnets" — especially since I highly doubt they'll coax Leonard Nimoy to return to the show in any active capacity. So a Bell-possessed Olivia is the only way we'll probably see Bell again.

Now at last we know why Peter and Olivia are important on FringeS

There's a lot to love about this episode, including some high-quality future dystopia. Full of fog and weird-colored lighting, plus curfews and checkpoints. (And also full of the Keystone Kops-level efficiency that pretty much every future dystopia has to exhibit, for the good guys to stand a chance.) But really, the main thing to love about this episode is John Noble getting to go all out as a subversive element in a world that's determined to crush him. Between last week's episode and this week's, it feels like Noble is making up for almost a whole season of Walter being cooped up in the lab.

There are almost too many great Walter moments to count in this episode. But they include: The brain-addled Walter repeating the word "liquorice" over and over. Walter reminiscing about monkey feces, brain-eating and LSD. A totally demented Walter casually fixing Nina's arm. The extended Obi-Wan Kenobi riff with the Evil Guard, who probably hasn't even seen Star Wars. (It's a dystopia, after all.) The way Walter starts chewing out his rescuers for tripping the alarms, once his brain is back together. The secret exit, because "Belly and I never left ourselves only one way out of a room." The way Walter sends his new friends off, and then slips away to create an anti-matter bomb. And then there's the way he gets William Bell to give him a hand with his problems.

Walter basically gets his Patrick Troughton on — the funny little man who runs rings around everybody else. (Except I can't quite picture the Second Doctor blowing up a building full of thugs and slicing his former best friend's hand off. That's cold.)

Now at last we know why Peter and Olivia are important on FringeS

All in all, the timeline in "Letters of Transit" does for Fringe precisely what "a timeline where Peter died as a child" failed to do. It recharges the show with a new level of possibility. It provides a new antagonist, one who's got more long-term potential than David Robert Jones, who's already died once. The show has a real mission statement again, and this new storyline turns the show's mythos on its side without contradicting anything we've previously learned. And it takes all of the (sometimes kind of annoying) hints that Peter and Olivia's romance was something the fate of worlds depended on, and gives us a concrete reason, in the form of the mentally gifted Henrietta.

All in all, a fifth season of Fringe suddenly feels like a much more intriguing prospect. As Hail Mary passes go, this one seems to have landed nicely.