Back at the Harvard lab, Astrid tells Walter that Nina checked Massive Dynamic's archives personally and couldn't find anything on this "Yatsko project," and Walter says that can't be right: "Belly and I created a serum similar to this in the mid-70s. I'm certain of it. We were trying to devise a method ... of questioning someone after death." He says this last bit thoughtfully, as if something just occurred to him. Was that thought "Hey, whatever happened to us questioning people after they died which was so big at the beginning of Season 1"? Anyway, Walter tells Astrid to tell Nina to look under "pet projects," because maybe the Yatsko research was folded into that, and I would imagine that Nina's search capabilities are sophisticated enough that she could have come up with that already. Walter talks like he thinks the Massive Dynamic archives are like a big card catalog.
And then Astrid briskly walks out the door like someone who actually has a personal life to go home to, as Peter comes in: "Don't let him keep you here too late, OK?" she tells Peter, before saying goodnight to Walter (getting a "goodnight, Esther" in return), who wants to smell something and tell his dad what he deduces, and Peter seems to be in such a good mood (maybe he's excited about the Celtics' ten-game winning streak?) that he isn't his usual sarcastic self when Walter asks him to do something so potentially gross and (in this lab) possibly fatal.
Anyway, Walter wants Peter to smell the corpse, and he does so. "I'm not vomiting," says Peter, and it must be a little unnerving to work in a place where not vomiting after smelling something is a pleasant surprise. "By now, it should be emitting the unmistakable odour of putrefaction. This corpse's decomposition has slowed to almost zero," says Walter, adding that he and Astrid (he gets Astrid's name right now that she's gone home) isolated some sort of serum in the corpse's blood, a preservative that's radically slowed cell degradation.
Peter wonders why the organ thief would slow down the guy's death since they'd stolen the heart, and Walter thinks it was a conscience thing; after all, the guy did call 911. "If the EMTs had got him on a heart-lung machine in time, he might have survived. It's highly unlikely, of course, but I'm betting it helps our organ thief sleep well at night," says Walter, which provides Peter with a nice little segue -- "Well, at least somebody is" -- into talking about his own problems. Walter takes that to mean that he hasn't told Olivia, and Peter proudly tells his dad that he in fact did tell Olivia, who took it "surprisingly well," according to Peter, and I guess the real reason that Peter didn't know Fauxlivia wasn't really Olivia is because he doesn't know anything about women IN GENERAL, let alone Olivia in particular. Walter's surprised to hear that, and asks if maybe they replaced Olivia with a robot. I think telling Olivia apart from a robot would be harder than telling her apart from Fauxlivia.