The bus investigation has commandeered a warehouse with the victims laid out, awaiting identification, their personal effects scattered about. What a lucky break! Someone was using a video camera on the bus to document their mundane rush-hour commute! Even more fortunate: the same solidifying goo that froze and suffocated everyone in place didn't gum it all up! And Olivia, who apparently has a photographic memory, instantly notes from a half-second flash on the video screen, that a woman's backpack seen in the video is missing from the bus. They quickly ID the woman as Evelina Mendoza, a federal employee: an undercover drug enforcement agent.
Olivia brings in Mendoza's handler, Grant Davidson, for questioning with her and Broyles, who says from her file it looks like Mendoza was an exemplary agent. Grant confirms she was, and then says three months ago she was tasked with infiltrating the East Coast representatives of a Nicaraguan drug cartel. Man. The most danger I'm exposed to at work is getting ink all over my hands from changing the fax machine cartridge.
Davidson says Mendoza recently called him to say she wanted out, because she got scared after hearing some drug lords talking about the Pattern. Even South American drug lords know about this thing? Man, was Olivia ever out of the loop. Grant says they were supposed to meet, but she never showed. Broyles says it appears as though the attacker was after something in her possession; does he have any idea what that could be? He doesn't and apologizes for not being more help.
Olivia takes Grant to the morgue so he can officially ID the body. They stare at Mendoza, laid out on the gurney. Olivia asks if she has any family. "There's a brother she doesn't talk to," he says, before having to turn away from the window. "I didn't realize how hard this was going to be," he says. Are there any male-female colleagues in this FBI not sleeping with each other? Olivia jumps at the chance to make this all about her, and says she knows what it's like to lose someone you've worked closely with.
Grant asks if he can "say goodbye," and he goes into the room to stand over the body and caress her arm.
Back at the Harvard lab, it looks like Astrid managed to score a sweet-sounding piano for Walter to noodle around on and not do any work. Olivia strolls in, and the sight of Walter playing the piano makes her smile. "Should I even ask?" she says. Astrid says the music really helps Walter concentrate, because as soon as Peter started playing, Walter was able to lock in; he's recreated the material found at the scene. "I hear you play the piano," Olivia says to Peter. "He doesn't just play; he's good. You should hear him," says Astrid, like LET ME KNOW WHEN YOU ARE ALL DONE FLIRTING WITH EACH OTHER. Walter blathers on about the composition of the material, and Olivia wants to know who would have the technology to make something like this. "I'll give you six guesses, and the first five don't count," says Peter. I guess that's because the first five would include SD6, Rambaldi, The Dharma Initiative, The Hanso Foundation... Olivia instantly guesses "Massive Dynamic!" and at this point Olivia should just stake out Massive Dynamic all the time, and save herself the trouble of constantly going back and forth.
Olivia's phone rings; it's Charlie, saying he's got something she's going to want to see. Later, he's leading her up the stairs of some apartment building, saying a priest alerted him to this guy saying something about the bus attack, before it happened. Roy McComb, high school graduate, works at an escrow company, where BPD is picking him up.
Olivia says he doesn't seem to fit the profile of a mass-murderer. "No. I didn't think so either," says Charlie. Then he leads her into Roy's room, which is covered with ghoulish drawings of death and destruction. Charlie tells her she's looking at depictions of hundreds of attacks, accidents and disasters over the past year, all of them dated before the events took place. Not just pictures either, but models, including one of a broken plane. "Is that the flight from Hamburg?" asks Olivia. Charlie nods. Look! There's an angry little Broyles stomping around and making fun of an FBI liaison!
The Fringe team watches Roy through a one-way window as he sits in an interrogation room. Peter lists a few of the disasters that Roy drew and skeptically asks if they think Roy could have been involved in all of that. Broyles admits that he doesn't: "But that doesn't make me any less interested in finding out where he got his information." Broyles adds that there were several cases that didn't receive media attention, and every one of them was drawn before the incident even happened.
Charlie goes in to talk to Roy, who seems helpful and co-operative, if nervous, as Charlie starts rifling through a pile of drawings to ask Roy about.
Wow, another faceoff between Olivia and Nina Sharp! Nina says the compound is supplied to a dozen labs, and any one of them could be where it was stolen from. Olivia reminds Nina that when they met, Nina said science and technology are at the point where they're impossible to control. "So far, all the science and technology that I've run across has been very tightly controlled by Massive Dynamic," she says, adding that every case has a connection back to the company. Nina says Olivia has it backwards: Massive Dynamic is so awesome that everyone uses its products, so sooner or later everything has a connection back to Massive Dynamic. Well, maybe, but we're not talking about products like Microsoft Word here, but advanced weapons technologies. Still, that's a much better argument than her second one, which points out that all the cases so far happened right in Olivia's "backyard," so does that mean Olivia's a suspect? Olivia is too stunned by Nina's dingbattery that she can't even respond, "That's because I live in Boston, stupid." Probably wants to keep that job offer open.
One of Nina's minions return with the files or whatever on this stuff, and she again demonstrates her higher level of clearance when she casually mentions that this stuff was used once before, in Prague, but with fewer casualties. But if Olivia had access to the case files, she'd know all this already, wouldn't she? I don't know how Nina earned such a high clearance level, since she never shuts up about this stuff.
Back at Roy's interrogation, Charlie is asking -- wait a second, why is Charlie leading the interrogation? He's not part of the team! Anyway, Charlie shows Roy his newest masterpiece, the woman with the bleeding hands, and asks if this is going to happen too. Roy says he knows it sounds crazy -- he himself thinks it's crazy -- but whenever he gets these feelings, it helps to get it down on paper. Or building it helps too. So it's kind of a supernatural masturbation, I suppose.
Roy says he's been getting these feelings for about nine months, which Broyles tells the fabulous Bishop boys is roughly how long they've been aware of the Pattern. "Meaning what, exactly?" asks Peter. Broyles says he's not sure. Maybe he should put McNulty on it. Still, Broyles doesn't think Roy's lying, and Peter says he's certain Roy isn't, because apparently Peter is an awesome poker player who can read people's tells. Yeah, don't mind the FBI with their years of training and experience, Peter: you play poker, after all.
Olivia shows up in time to hear Walter put forth his Occam's Razor hypothesis (i.e. the simplest solution is usually the right one), which is that Roy is psychic. "Theoretically it's all quite possible," says Walter in the face of Broyles' skepticism. He figures Roy doesn't have any control over his abilities -- he can't read people's minds -- but he's linked psychically to a person or small group of people responsible for these events, or even just discussing them. Broyles is all "I'm skeptical" so Walter wants a chance to prove it. Broyles asks him how he would do that. "Am I required to keep him alive?" asks Walter. Hee. Olivia overplays it, telling Walter th