Last night’s thrilling Fringe episode may have been titled “Momentum Deferred,” a reference to physics, but as William Bell (Leonard Nimoy) said, quoting Walter Bishop, “Physics is a bitch.” No, what they should have called this episode is “Ring My Bell,” after the great 1979 Anita Ward hit. For it was by the striking of a bell that Olivia was jarred out of a new alternate-world visit with William Bell, and this time, she remembered what he said… which was nothing less than a warning about a pending Armageddon in “our” world (i.e., “the last great storm”; “an inter-dimensional war”).

But I’m getting ahead of myself. The hour began with bad guys (it’s still a tad disorienting to see Roger Cross — the late Curtis Manning from 24 — among the villains) hijacking a truck filled with cryogenically-preserved heads. There’s a shoot-out; a dead man’s body bleeds mercury, and Walter finds on the crime scene one of the devices “the shape-shifter used” in a previous episode, except this one’s intact. There’s some quick interaction between Cross’ character and the shape-shifter-possessed Charlie, who’s acting increasingly strange: “You’ve been in that body too long. You’re dying.” Uh-oh: things are not looking good for Kirk Acevedo’s continuing Charlie role…

The night also began with Walter’s latest attempt, back in the lab, to help Olivia regain her earlier memories, this time by having her drink an earthworm shake whipped up by Astrid in a blender: comic relief with a purpose.

Next, remember the hippie girl we saw on an old videotape in an earlier episode, the one Bishop and Bell pumped full of LSD and got her babbling about “soldiers from somewhere else”? Well, she grew up to be guest star Theresa Russell, who, as Rebecca Kidner, agrees to undergo another such test in Walter’s lab to try and get back some of her memories. (What is it with Fringe and men digging into women’s memory banks?) By the way, before he sends Rebecca tripping on “homemade psycho-tropic drugs,” Walter plays Yes’ 1971 “I See All Good People” as a mood-enhancer and a lyrical comment on what’s going on: that is, in the past, good people have turned their heads and ignored possible evil in the world, something for which Walter hopes to make amends. While also extracting more info for the present case, of course.

While Walter was puttering around with Rebecca, Peter struck a bell — and immediately Olivia, who’d just been observing, was thrown into the alt-world and her meeting with William Bell. This resulted in one of the most emotional and fierce scenes in Fringe‘s short history, as Olivia stood her ground against Bell’s silky assurances and chattiness. When he reminded her of the name she used to call him “when you were a girl,” Olivia became ferociously angry, bringing up the long-ago “drug trials on young children” — who included Olivia. “We weren’t trying to hurt anyone,” said Bell.

“Guess what?” said Olivia coldly. “You did… I don’t trust you, Dr. Bell.” This was an abuser being confronted by his abused victim. (Question: Since Walter was Bell’s partner in these experiments, does she feel the same rage toward Walter, and has tamped it down because of her fondness for the man and his son?)

Undeterred, “Belly” (what a terrific, coolly-controlled performance Leonard Nimoy gave here tonight) knew this was his brief chance to tell Olivia about the “coming war” and the “hybrids, part organic tissue, part machines.” These are The First Wave, and to combat it requires a “guardian… between this side and yours,” said Bell. He indicated that Olivia is meant to be that guardian: “You are the one, Olivia.”

I haven’t had a chance to mention Nina Sharp’s presence in this hour, so I’ll say here that Olivia brought her the odd semi-circle symbol that Bell gave the FBI agent to show to Nina.

And then, as though there wasn’t enough info and action packed into this hour, poor, tortured, soul-robbed Charlie made his move, trying to convince Olivia that Nina is the shape-shifter, but only tipping his hand that he is. So Olivia shot and killed him. The rumors of Kirk Acevedo leaving the series seem to be true… unless he comes back in some other way/shape/form/universe-location.

Fringe wrapped up with the cliffhanger of the cryogenic head sought by The First Wave being grafted onto a body, thereby getting a super-soldier ready to cause havoc in the weeks to come.

I continue to admire the way Fringe can mind-meld its scientific fiction with workplace-family drama and light comedy, juggling an increasing number of characters and subplots, while still maintaining a strong narrative through-line. My guess is that one of the next steps in Fringe‘s storytelling is to bring Peter, already displaced in the two universes, into the inter-dimensional war more actively.

And I’d like to see more of Nina Sharp’s lab assistant Brendan — funny guy, wasn’t he?

So what did you think of this jam-packed hour?