Anyway, Walter's not coming up with anything as a result of the autopsy, but he needs the other body so Broyles tells Olivia to go fetch it with Lee while Broyles goes to tell Walter that the boy is here.
Olivia goes over to sit next to Aaron and tell him that she likes to draw too. There, that should sufficiently bond her to the mini-human! That done, she tells Aaron they're going to have him checked out to see if he's OK, and their friend Dr. Bishop is going to examine him.
"I don't like doctors. They scare me," says Aaron, and Olivia, perhaps not thinking this through, tells Aaron that there's nothing scary about Walter. That's when Walter shows up decked out in trés chic Mad Scientist: heavy rubber gloves, visor, blood-spattered apron. The usual. "All right, young man, let's get started. Take off your shirt and get on the table," Walter says, all business.
So cut to the kid (shirt on) sitting on the table, with Manfred Mann singing "The Mighty Quinn" in the background. "Please, I don't want a shot," says Aaron, and Walter says that, technically, a shot deposits a substance in the bloodstream, whilst this is a withdrawal, like I don't think it's the substance-deposit that the kid is scared of but THE ACTUAL NEEDLE, WALTER. Anyway, Walter promises that it will be just this one time (like Walter can EVER promise to give someone only one needle) and Aaron nods. Walter takes the blood sample and puts it in the centrifuge while Aaron hops down from the table and goes poking around Walter's lab, touching the mounted skeleton of some small creature, and then picking up a G.I. Joe sitting atop a red truck among some other toys.
Walter glances over and sees Aaron with the toy and then starts yelling at the poor kid not to touch it, and snatches it from him. He composes himself soon enough, and tries to reassure Aaron that it's OK. It's just that the toy belonged to his son. "You have a son?" says Aaron. "I did. He died," says Walter. Somebody get Aaron out of here before he's traumatized for life!
Anyway, Astrid comes in and says Walter needs to have a look at something. She takes him over to the corpse and holds a lit candle near the body. The candle blows out. Then she shows him the lambda sensor (Lambda House rules!). "The corpse is pulling high levels of oxygen out of the air," says Walter. He looks closely at the body, and how many shows can you watch where you're going to hear someone saying something like, "I don't remember there being this much mold on the ribcage before"? He examines the body with a magnifying glass, and we can see the mold starting to swell. Walter frantically tells Astrid to get the incubation case. Fortunately it's right next the table, and Astrid wheels it over, and they dump the body inside.