Peter sarcastically suggests that he should have followed in his dad's footsteps, since Walter's work has "obviously brought so much joy to the world." Peter, no, that's Three Dog Night. You're thinking of Three Dog Night. But suddenly Walter sharpens and asks Peter who the guy in the diner was: "You in some kind of trouble?" Peter laughs it off, and says the guy was just harassing the waitress, so Peter just told him to knock it off. "Oh, I see," says Walter, clearly not buying it.
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.