On the twenty-third floor, the security guard lets Walter go right on through, but tells Duffy that he's not allowed to be up here: "Police are strictly working the lobby." Duffy more or less ignores him and kind of cocks his head, watching Walter continue on. "Sir," says the security guard. Likely the last word he'll ever speak.
Back in the cafeteria, Peter and Fauxlivia are talking about Patricia Van Horn not knowing her husband wasn't actually there anymore, with Fauxlivia arguing the "shapeshifters are amazing!" side of the argument. Peter wonders if maybe she DID notice but just made excuses or came up with ways to explain it to herself: "Kind of like I've been doing with you," he says, giving Fauxlivia yet another "Oh shit! My cover's blown!" scare, only Peter is just referring to "all the little differences" he's noticed in her since she's been back from the other side. "It's like you're a completely different person," he says, including her seeming less burdened and more patient with Walter. "Don't get me wrong, I like it. The change is good. But it's different." Fauxlivia, you really shouldn't be looking THAT nervous right now. They're joined by Astrid, who of course doesn't know where Walter is, causing Peter to spring into action.
Upstairs, Walter is wrestling with Van Horn's body, rolling it over so he can make an incision in the base of the spine (mercury spilling out). Officer Ray Duff comes strolling in and tells him to step away from the body, and Walter goes full-on fraidy-cat, holding his hands up, but while Duffy pokes around inside (the conveniently pre-opened) Van Horn, Walter grabs hold of what looks like some kind of surgical steak knife.Duffy pulls a little doohickey out of the back of Van Horn, and Walter's not so terrified that he can't be excited over being right about the memory being in the base of the spine. "Yeah, you were right," says Duffy, not even looking at Walter, who closes his eyes, looks like he thinks that what he's about to do will likely result in his own death -- and he jams the blade into Duffy, who pulls it out and then grabs Walter and slams him hard against a beam. Downstairs, Fauxlivia and Peter get on the elevator that Duffy vacates, and Peter notices, too late to get out the closing elevator doors, the splotches of mercury that must have come from the cop. Fauxlivia hits the button for the second floor and tells Peter to look for Walter, while she goes after the shapeshifter.