As for Olivia, she's too busy hallucinating John Scott in the crowd gawking at the crime scene to investigate much of anything.
But now Olivia's inside, talking to Nina Sharp, because no one else but Nina Sharp out of a company of 300,000 can talk to Olivia. She says, "Mark Young was a capable executive who displayed no signs of emotional dysfunction." Wow, someone's going the extra mile for a heart-wrenching eulogy. Nina sounds callous, but, essentially, shit happens and a small percentage succumb to the stress of their responsibilities, "and, on occasion, the nature of our work." And Olivia's all, "What work would THAT be?" and Nina's evasive and mutters something about delivering results. Then she makes another subtle pitch at hiring Olivia, who isn't having it, and gets really annoyed about only getting "the polite appearance of co-operation." Nina rattles off some nonsense about being on the cutting edge of science and the risk of "exposure to ideas that aren't easy to reconcile," whatever that's supposed to mean.
We go over to Mark Young's apartment, where Charlie is checking out a mill bottle and wondering how the human race survived without drugs, and thankfully Olivia and the forensics team are just outright IGNORING him. Some forensics chick tells Olivia that the hard drive is password protected, but they'll send her the data after they break it.
Olivia and Charlie keep looking around, and Olivia finds a plane ticket Mark bought three years ago, suggesting he wasn't planning to kill himself, except Charlie points out that it's "Christmas in Nebraska" which is depressing for some reason that he doesn't care to elaborate on.
They keep looking, and Olivia picks up a day planner on a desk. She flips it open and finds the word "MONARCH" written on a page. Then she notices the mounted butterflies on the wall behind the computer. As she watches them, they start to rustle their wings. She's mesmerized. She needs to stop staring at things! Charlie startles her, and she says she hasn't found anything. Technically that might be true, as she's been going crazy all season.
Back at Walter's lab, he's saying that his suspicions are correct: the wounds go down to the bone itself, as if they originated on the inside and pierced their way up through the body tissue, and of course no one has any idea how that could have happed. Walter studies the blood sample data Peter gives him so he can see anything untoward. There are no illegal drugs in the dude's system, says Walter, but one of the medications could be used as a carrier to "transfer the foreign compound to the victim's brain," and of course no one in the rest of the lab ever heard him say ANYTHING about a "foreign compound." And before he can explain, he just rambles on about how Peter only ever wanted "coffee yogurt" when he was 13. "Walter, that wasn't me. That was you," says Peter. So it was, remembers Walter, who goes back to work while Peter's cellphone's ringing. Walter tells him to ask Olivia for coffee yogurt, and then admits to Astrid he can get obsessive over things. Astrid dryly gives him a "Really?" Peter goes off into a private room while the woman on the other end of the line says she didn't know what hearing Peter's voice would do to her. Shudder? Cringe? She tells him, cutting him off, not to bother making up a story. She needs to see him. Peter's reluctant, but it looks like they're gong to work out the where and when.