In a drawer, Olivia finds a receipt for a certified cheque for $30,000 from someone named Isaac Winters. Charlie tops her in the discovery department, though: he brings Olivia to the bathroom, which is charred and blackened beyond any use. There are fire extinguishers in the bathtub. "What the hell happened to her?" asks Olivia. Whatever it is, that damage deposit is staying right where it is.
Back at Harvard, Walter's going through his boxes when Peter comes in with bags of groceries, and he's carrying them in paper bags, like who even USES paper bags anymore? I miss paper bags. Walter asks if Peter got it, and Peter says he told his dad they didn't have it. And Walter insists that he needs Frankenberry, because that's what he was eating back then, so it's crucial for him to recreate the sense memory if he's to remember where he put the manuscript. "For all we know, they don't make it anymore," says Peter, who got his dad something called "Boom Berry," which he calls "all the artificial sugary sweetness a growing scientist needs."
Olivia comes in, and Walter guesses that she's a "Corn Flakes" girl, and Olivia's all, "yeah, why not," since she's learned by now not to ask too many questions when Walter's off on one of his little tangents, and she just wants to work. She tells the Bishops about the evidence of other fires in Pratt's apartment. Walter says that changes everything: "We can rule out spontaneous combustion. For one, I mean, that's strictly a one-off event, as you can imagine." He thinks it might be pyrokinesis, which has Peter complaining that there's no time for jokes, which is HILARIOUS coming from Peter. "It's not even a real word. It was made up by Stephen King. You ever see Firestarter with Drew Barrymore? Little girl who can start fires with her mind?" I think you're thinking of Boys on the Side, Peter. Walter says Stephen King (who he calls "Mister King") coined the term, but "the phenomenon existed long before that." He says it's not really complicated, just a form of telekinesis. Which also totally exists, I suppose? Then he uses the box of Boom Berry that he's holding to demonstrate how you excite the molecules (in this case, individual Boom ... berries?), so they vibrate more quickly, generating heat and then eventually you spill Boom Berry all over the laboratory. Peter calls it a fascinating demonstration. "But it still doesn't explain why it is that Susan Pratt blew up." Walter says it must have been a newfound ability, as it takes training to generate a heat source outside of the body. Ah. So she should have gone to Human Torch School. "Without proper control, the energy is turned inward. You see? She had no other options," says Walter. Peter summarizes Walter's theory as: "You think that she had a choice to either blow somebody else up or blow herself up." That's it; Walter says the woman was a powder keg, and emotional stress or agitation would have set her off. Olivia asks where the ability came from: "Is it that she was born different or is it something that someone did to her?" Walter calls that the real question.