A swarm of black vehicles swoops in around the station, and the Fringe team steps into a mobile command center set up in the back of a surveillance van. From here, they can see a live video feed of Burgess getting out of her taxi in front of the station and answering her red phone, apparently unaware of the government dragnet forming just blocks away. The A/V agent running the bank of equipment in the van tells Broyles that they can't tap into Burgess's phone because it's encrypted. I would think they couldn't tap into it because they don't know anything about it, but I'm just an ignorant civilian. The field agents report by walkie-talkie that Colonel Gordon hasn't been sighted outside the station. Walter speaks up, asking about the EMP disabling devices that Peter saw earlier. When Broyles confirms that the station would have them as well (though again, without explaining what they are), Walter says that means they would jam any radio trigger. Which in turn means that Gordon would have to be inside the building to send the trigger signal. Peter realizes Walter's suggesting they triangulate Gordon's position when he broadcasts the signal. "But in order to do that, we would have to leave the frequency open. We can't jam it." Olivia agrees that this could be their only chance to get Gordon. After hearing Walter's guess that they'd have thirty seconds form signal to boom, Broyles gives the order to let Burgess go inside, and dispatches Olivia and Peter into the building. What could go wrong? I mean, aside from another Philadelphia tragedy but with the added benefit of it having occurred while the FBI watched with its thumb up its ass?
Waiting inside the station, Burgess gets one last call from the Colonel, telling her to "accept" a black briefcase from a guy in a black trenchcoat and then head back to her hotel. She hangs up and starts looking around. She doesn't notice Peter and Olivia, who are also scanning the station and hearing Broyles tell them over CTU-style earpieces where Burgess is, and that although they're scanning for a 331.6 MHz radio signal, they haven't detected one yet. They spot her. A moment later, Burgess spots a guy with a black trenchcoat and a black briefcase. An entirely different one than before, obviously, since that guy got blowed up. As Burgess heads over to intercept him, the monitor in the command center lights up, "SIGNAL DETECTED." Good thing Walter's in there to explain what that means. "She'll detonate in thirty seconds," he reminds everyone. The A/V agent can't get a fix on the signal, though; it's not only arming the device that is Diane Burgess, it's also fucking up the FBI's gear. Which means Olivia and Peter are on their own. Walter's slowly counting, "one Mississippi...two Mississippi" in the van (get that man a stopwatch), as Olivia tells her earpiece that the guy Burgess is talking to is not Gordon. I don't know why her radio link to the van is still working. Broyles gives the order to jam the signal, but that doesn't work. "We have a problem," Broyles says into his walkie. "Dunham, attempts to jam the signal have failed. She's going to detonate." Yeah, Olivia probably figured that out by looking at the flickering schedule monitor she's standing right next to. I'd get behind it if I were her. Or better yet, behind a monitor in a different train station.