Our favorite remorseful maniac, Walter Bishop, almost completely stole last night's episode of Fringe — except that some very poignant Peter/Olivia moments demanded our attention as well. Here are the 10 greatest Walter Bishop moments from last night's Fringe.

The 10 clips above, in order, are:
1) Walter makes breakfast for Peter and Olivia. And apparently he thinks bacon is called "pig's bum." Or that's just what fits in with the song he's attempting to make up about breakfast.

2) Breakfast is the most important meal of the day — Walter proved this in 1973! How did he prove it? What sort of experiment did he do, and how much LSD was there in the orange juice? What was the control group?

3) Walter sneakily ducks out of the house while Peter and Olivia are making awkward small talk, so those kids can have some real "trapped with pancakes" time together.

4) When Walter hears how his match-making turned out, his immediate reaction is, "Should have made a frittata." Because no star-crossed lovers (universe-crossed lovers?) can resist a frittata.

5) Like a flash mob of suicide.

6) Walter flipping a coin over and over again, and the look of growing horror on his face as he gets heads each time. You don't even need to know how the coin is coming up — I guessed what was going on just from the way Walter was staring.

7) Walter, freaking out that his universe might be starting to unravel the way the other universe has, doesn't quite have time to say "thank you." When Olivia suggests he should remember the magic word, he's like "I'll say 'hocus pocus' if it means you'll do your freakin jobs."

8) Instead of explaining why he needs some old case files to Astrid (the way a good mad scientist is supposed to), he gets even testier. I love "is it second-guess-everything-I-do day?" And I love that guilt and anxiety don't make Walter more childlike as you'd have expected — instead, they make him kind of obnoxious.

9) And this is the crux of the episode — faced with the prospect of a crack in his universe that could turn into a vortex, Walter is being drawn towards making the same decision that Walternate made: Seal the breach using amber. That choice will erode what little claim Walter has to being less ruthless than Walternate. (And he can't know that last week, Walternate faced the same choice as Walter — whether to test cortexiphan on small children — and made the less-evil choice.) More than ever, we can't really be sure which is the "good" Walter, and this realization is dawning on our Walter. It's almost as painful as the prospect of reality falling apart.

10) At the end of the episode, the prospect of a catastrophic vortex has been averted, but Walter knows he's just delayed the inevitable. He doesn't know how to prevent the cracks from appearing, or what to do about them. And then Nina, who's been in danger of turning into just a shoulder for Walter to cry on lately, says something really interesting: "Well then, I think you need to learn." And Walter goes through about five different expressions on hearing this. Including a flash of elation at the idea of learning something he doesn't know. And something curiously akin to humility at the realization that there's stuff he doesn't know, that there are answers he doesn't have yet. And that, right there, is why we love this Walter, and why he may be the "good" Walter after all. Because he's done some terrible things, but he's come out of it with a bit more humility. Unlike Walternate, whose main characteristic seems to be a need to appear to be in control all the time, Walter has accepted that he's often at the mercy of the universe. Which is why Walter may be more able to learn than Walternate. It's curious how much that phrase seems to comfort Walter.

So yeah, this was the first sign that our universe is not as stable as we'd hoped — and fittingly, the realization came during a big Tom Stoppard tribute. The building where the breach in the wall between universes occurred is the Rosenkrantz building, named for Stoppard's play Rosenkrantz and Guildenstern are Dead. Rosenkrantz and Guildenstern are two minor characters in Shakespeare's Hamlet, and Stoppard plays with the idea that they're hapless victims of the larger story they're stuck in. He also plays with causality by having them flip a coin that turns up heads each time — just as Walter's coin does.

You have to wonder if this means that there's a larger storyline taking place that we're only seeing glimpses of, much as Rosenkrantz and Guildenstern only see glimpses of the story of Hamlet? Possibly it's a story written long ago by the First People, or possibly it concerns a hero we've barely even met? Or maybe the Stoppard references are supposed to convey that the universe is capricious and drives us towards a particular end, even while we cling to the illusion of free will? Maybe there's a tragedy in Walter's future that he can't change, any more than he can make one of those coin tosses come up tails?

The other big reference I caught is that the woman at the start of the episode is leaving the Rosenkrantz building forever, and moving into the Schrodinger Motel. Presumably this is a place where all the rooms are in a quantum state, and the beds are both made and unmade, until you open the door. More to the point, though, Schrodinger coined the term "entanglement," in which two particles can be in a relationship despite being far apart. And last night's episode contained the second suggestion that things could be entangled between the two universes — the first being that typewriter that Fauxlivia and Newton used to communicate with the other side.

This time around, it was a grieving widow on this side and a grieving widower on the other side who became entangled. A couple months earlier, a fuse blew in their apartment in both universes. And they tossed a coin to see who would go replace it. (The coin toss again!) In this universe, the husband went, and was electrocuted. In the other universe, the wife got zapped. Because the wife "over here" and the husband "over there" were both grieving, their bodies made a kind of natural equivalent to cortexiphan, and they were able to see each other — thinking they were seeing ghosts.

And in the end of the episode, the breach between universes is only stopped when the wife realizes that's not really the ghost of her husband, and she needs to let go of him once and for all. It's a bit of a flimsy plot, to be honest, and the final scene of Olivia and Peter telling the widow to let go was pretty much the only weak scene in the whole episode. But like so many other episodes lately, it's only there as a kind of grace note and impetus to the stories of our main characters. (Really, Fringe needs to pull out a good solid "A" plot one of these weeks, just to prove they can still do it.)

The "entangled widow/widower" plot served to kickstart the "cracks in the universe" storyline — but its main function was to illuminate the Peter/Olivia relationship. Like I said, there were some really neat, poignant moments between Peter and Olivia last night, which made their relationship feel real, and quite different from the Peter/Fauxlivia affair.

Olivia confronts Peter about the fact that he hasn't been honest with her about Fauxlivia. And in response, Peter is slightly less dishonest than before. Yes, he still thinks about her, but only because he got to have this beautiful thing with her, and he knows it could be beautiful with Olivia too. For a con-man, Peter is kind of a mediocre liar, and Olivia seems doubtful — but then he throws it back onto her: Fauxlivia isn't there to come between them any more, so who's really stopping them from being together?

Later, Walter makes a more successful attempt at pushing those kids together than his failed pancake gambit. He makes them install seismograph equipment at the building in Brooklyn, and then wait on site, in the freezing cold, in case he has any calibrations. (A side note: Is it a sign of the universe unraveling that Cambridge, Mass. and Brooklyn are apparently right next to each other now? People kept popping back and forth. Or was it actually Brookline, and I just misread?) Peter and Olivia wind up waiting in a bar, where Peter puts on some Stevie Wonder.

And Olivia's almost convinced to try again with Peter — but when she kisses him, he starts glimmering. Because whenever Olivia feels fear, she can see a kind of glow emanating from things from the other universe. And Peter's from the other universe. So Olivia's still feeling afraid, and maybe it's true that she's keeping them apart because she's too screwed up to make it work.

There's some marvelously subtle acting from Anna Torv — as well as the unappreciated Joshua Jackson — in this episode.

And in the final moments, Olivia gets over her fears because of the thing that Peter told old Mrs. Entangled about how most people don't get to have a whole life with the person they love. So she leads him upstairs to his bedroom — where I'm guessing they'll be woken by Walter bursting in with a frittata in the morning. (I know, Walter's in New York. But see above for the folding of time and space, or the way-faster Acela trains, in the Fringe-verse.)

So the episode left us with some shoes still to drop — like how things will change when Peter finds out about the bun in Fauxlivia's oven. And just what Walter will do the next time there's a hole in reality.

But first, we get another flashback episode, this time showing that Peter and Olivia actually met when they were kids. This could be one soap-operatic leap too far, or it could be a great deepening of the characters and the mythos. Let's hope for the latter. Here's the first sneak peek from next week's episode: