He says he thinks there are eight or nine voices, but not always and some of them he doesn't hear for weeks. Last night there were three -- which Lincoln tells everyone is how many assailants the police suspect there were -- but then one of them left while the other two went to a subway station. So not to the sandwich shop, then. "I heard them say that one of them was hurt, like he was cut. He needed to get cleaned up before he got on the train," says Sean, adding that it was in the bathroom. That's the last thing he remembers before the sedative started working and he fell asleep.
While Lincoln gets down to the business of arranging the search of subway stations near the victim's home, Walter asks Sean if the voices speak directly to him. They don't, he says, at all. "They only speak to each other?" asks Walter, which Sean confirms. Olivia asks what Walter is thinking, but Walter just asks Sean if he'd be willing to go off his meds if it would help the investigation.
We don't see Sean's answer, but we do see Walter later walk down the hall to Bernadette, who's giving Sean's medical records to Astrid. Walter tells her that he thinks her diagnosis of Sean is fundamentally flawed, and he says it about as tactfully as we all know Walter would, practically spitting it in her face. He points out that the voices Sean hears don't persecute or relate to him at all. "In fact, recent evidence proves that what he's hearing are the real thoughts of other people," snaps Walter, who both as a scientist and someone who works with the FBI probably knows the difference between "this person says this happened" and "proof." At any rate, Olivia looks like she wants to crawl under a rock when Walter starts talking about "psychological symbiosis" and "mental telepathy," but she is on board with Sean agreeing to go off his meds, even if Bernadette looks like she doesn't think that's such a hot idea. "We're hoping that the more he is able to hear the voices, the more likely it is that we will be able to catch whoever's responsible for the killing," Olivia explains. Bernadette reveals that this is a bit of a One Flew Over the Cuckoo's Nest thing and that Sean is here voluntarily, so he can do what he wants, but she's still going to explain it to his prescribing physician. Olivia offers to come with her: "That way I can keep walking around this mental hospital and continue having flashbacks of memories that belong to another Olivia," she says. Which she then does!