I'm sure we're all surprised to learn that using alien technology to blow up a time-travel portal to the future isn't a walk in the park, but let's let hear Walter out! Because that means he's going to demonstrate using toys! Damn, it's been a while! He has little dinky cars and army men on top of a sheet with a hole in it, the hole one end of a tube down to a bottom part. Everything on top of the sheet is the future, Walter explains and when the Observers transport from their future to our present, it goes down a wormhole that's stable at both ends, so matter and energy in their future is unaffected. To demonstrate, Walter drops some marbles down the tube. I like to think Astrid spent several hours freeing Walter's toys from the amber for just this type of demonstration.
Anyway, if we in the present were to collapse our end of the wormhole, then everything they put down it, will just weigh it down. Walter demonstrates, cutting the tube and sealing it, and then dropping more marbles into the pipe, dragging the sheet down, sending the toys tumbling into the hole too. "The result is like a vacuum, sucking all matter and energy into itself, consuming it."
Peter sums it up: "You wanna turn the wormhole into a black hole," he says. Well, technically Peter, you do and Walter is just indulging you. Anyway, how to collapse the wormhole, leaving a black hole "and a hell of a lot of destruction" on their side?
Anti-matter is the answer. "The batons that we got in Etta's apartment," says Peter. Or the ones you got from Broyles, remember? You know, like the one Etta used to force you guys to leave her dying body? Yeah, those ones. Peter goes and grabs one, but then points out he's still going to need to get close enough to throw one into the corridor. Well, you really only have to get within a hundred meters, really. And plus, at the end of the last episode you demonstrated just how far you can run in twenty-six seconds, so it shouldn't be that difficult, even as Olivia -- she and Astrid have just strolled in -- points out that the place is going to be crawling with Observers and Loyalists waiting for it. I'm hearing lots of problems, but no solutions!
Walter says that's where the cube comes in -- he says the swirls of static electricity right before the corridor opened is like a telephone ringing, a phone call from the future. "The cube answers that call and the corridor is opened," he says. "So we just have to answer the call first," says Peter. Look, at some point, these similes are a little too simplistic, right?