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!