Last night's Fringe spanned the two parallel realities like never before, with "our" Olivia crossing over to the alternate reality to catch a serial killer using a special informant from "our" world... Unsurprisingly, we've got five questions about "One Night In October"'s magical mystery tour.

What Happened When Olivia Was Kidnapped?

We know that time has been rewritten with the conclusion of the previous season, but it's still uncertain just what has changed - and why, beyond the whims of the writers' room. This episode had an unexpected revision: The "Over There" Broyles was still alive, which meant that whatever happened to return the two Olivias to their respective Earths, it wasn't the same as what we saw last year. Whether we'll ever find out what did happen is open to question, but given that Fauxlivia's escape route was different, it leads me to wonder if "Our" Olivia's was, as well. Which, in turn, leads me to wonder...

Did William Bell Exist?

A second week with no mention of Massive Dynamic, which is either a strange coincidence - How many episodes in previous seasons didn't include at least a mention of the place? - or something more important. Between this, the revised history of Walter Bishop and the suggestion that things with Olivia last year didn't go down as planned, I find myself wondering: What if William Bell didn't exist in the new timelines, or at least, didn't have the same history as we know about? What if he didn't found Massive Dynamic or cross over into the other Earth?

Is "Our" Earth Kinder?

"Our" John met Marjorie, who took him away from his serial killer tendencies. Our Olivia and Walter may have their quirks, but they're also arguably warmer, kinder people than their alternates - well, not so arguably in Walter's case - and our Earth isn't, yet, an ecological disaster filled with Police State mentalities. Is our Fringe Earth kinder, or better, than the alternate Earth? I find myself thinking about DC Comics' multiverse, and not for the first time. In Grant Morrison's JLA: Earth 2 graphic novel, he suggests that the regular DC Earth is one where the good guys ultimately win, but Earth-2 is a place where the opposite is true, and the natural order trends towards corruption, betrayal and disillusionment. I wonder if the Fringe writers are fans of that book, at all...

(Only tangentally connected, but I adore Anna Torv's different Olivia's, and the fact that Fauxlivia has a slightly different accent that's more like a character from an old film noir. It's so subtle, and yet so important, somehow.)

What's With The Cyborg Other Earth?

It can't be coincidence that the alternate John had a plug-in port in the back of his head in the same episode that Walter told Lincoln that the technology from the alternate Earth was organic in nature. Is there something important about the prevalence of cyborg tech over there? And if so, what...?

Where Is Peter?

Peter is, according to the end of the episode, trapped outside of reality somehow and trying to escape. I find myself thinking about DC Comics, again, and the idea that jumping from one Earth to another was a matter of changing vibrational frequencies. After all, didn't it look as if Peter was vibrated out of reality, at the end of season three...? I have the feeling that Peter was never really erased from time at all, as just shunted outside of it, somehow... and that that was the work of the observers, as opposed to any natural phenomenon. If so: Where is Peter, and why are the observers trying to manipulate events in this way?