Harris starts to walk away, but Olivia stops him with a little speech about how she knows he doesn't like her and thinks she's bad at her job: "But please, don't let that get in the way of doing the right thing. That man in there may likely die if we don't keep him safe." Olivia says she's not asking Harris to like her: "I'm asking you to do the right thing."
Harris thinks it over. "Yeah, we'll keep him safe," he says (well, for the next couple of minutes, anyway. Spoiler alert!), and gets on the elevator and frowns at the wall.
Her cellphone rings. It's Peter, calling to tell her that Walter's made a breakthrough. The slug was activated by liquid. Turns out the yellow powdery stuff in the vials Olivia took are eggs, and the catalyst is stomach acid. "So the victim just needs to ingest it?" says Olivia. Or just pick up some stomach acid at the grocery store, Olivia. You don't want to get it at the convenience store. It's much more expensive there. Anyway, Peter says that once that happens, the thing grows, very quickly.
As they speak, we watch some torso pour a glass of water and dump some of the powdery yellow stuff in it. Why hide the face? Is there any reason we shouldn't already know this is Mitchell Loeb? The guy's face is hidden right up until the glass of water is delivered to Dr. Simon who thanks Loeb.
Loeb leaves and Simon takes a drink just before Charlie comes in to take Simon to the field office for debriefing before they move him to a safe house. But he's not even finished speaking before Simon starts looking uncomfortable. And maybe Charlie should have been briefed on exactly what Kinberg did before he died so he might have recognized this a bit quicker? Simon sounds like he's got the dry heaves, and Charlie says into the room's intercom that he needs medical assistance. He goes back over to Simon, who coughs blood on him and then collapses on the floor, where, much to Charlie's disgust, he starts to vomit out another one of those slimy things. "Oh, my god," says Charlie, looking thoroughly grossed out. He's not too freaked out, though, to pull out his gun and start SHOOTING at the thing, just as Olivia walks in. I hope Charlie hit it, because Olivia's just STANDING there with the door wide open.
Yeah, looks like it's dead. Walter's gleefully taking it out of a box and talking about what gargantuan specimen of nasopharyngitis it is. Olivia's all, "what does that mean?" like Peter's really falling down on the job of translating his dad's science jargon today, and Walter says it's a single specimen of a virus for the common cold. "So you're saying that this is one single cell?" says Olivia. Walter points out that an ostrich egg is a single cell, and it can grow up to five pounds. Is that true? I'm going to have to write the encyclopedia people and find out.