Walter explains to the rest of the team that the escalator is infested with nanites and Astrid explains for Olivia (the only one of the team who wouldn't know) that nanites are microscopic self-replicating robotics and there's a machine generating them on the escalator. Walter says that despite their itty-bitty size (good to see he's using proper scientific measurement terms), each of them is capable of storing a tremendous amount of energy and it appears they can be overloaded by the bio-kinetic energy in the cells of anyone infected. "You mean, these people's movement is what's activating the nanites?" says Peter, surprised, even though you'd think that was already a theory that's been discussed, given the woman who figured it out INSTANTLY and the reason the survivors have been standing still for hours.
Walter, annoyed, says that's what he just said, adding that the longer the nanites are in the bloodstream, the more sensitive they become so the slightest exertion can trigger the overload, causing them to spontaneously combust. I have no idea how much of this is bullshit, by the way, besides "most of it."
Olivia, as always, wants to get to the practical side of things: Who would do this, and how do they stop it. Walter says he doesn't know and he needs his lab, but the rest of them are too concerned about the danger of transporting them. Walter says he's not sure how long they have left even without moving them. That's when Walter's new friend speaks up, asking if they have any kind of insurance: like if she volunteers for the experiment and something goes wrong, what happens to her next of kin? Astrid says the Bureau would take care of her: "Everybody that we work on is full covered. It's in the regs," she says. You know, it's almost unbelievable that this hasn't come up before now.
Anyway, she volunteers, saying, "You can use me, for whatever you need." I have a violent coughing fit. Olivia asks her name; it's Jessica Holt. Olivia wants to make sure Jessica knows exactly what she's saying and Jessica says she does and Walter calls for a solid-board stretcher, some ice packs and a blanket. Time to get the party started! Or not so much party, but a potentially lethal transport during which the slightest movement could kill this poor woman.
After the commercial break, the team has managed to get Jessica back to Harvard and into Walter's lab without burning her like a marshmallow in a campfire. Olivia says it must all seem a little bizarre to her and Jessica says that she's an ER nurse and "night shifts on Fridays" are what's bizarre.