After she and Lincoln leave, Walter gets pissy with Peter, saying he knows what Peter's doing: "I know what it's like to want something back that you loved. I have succumbed to that temptation myself," he says. Peter, rolling his eyes, says that whatever's happening to Olivia, he's not doing it. Walter thinks he is, even if he doesn't realize it. "And it's wrong, Peter," he says. Uh, it's wrong even if Peter's not able to control whatever it is that's happening?
Anyway, Sean's mother lives in Florence, Massachusetts, and she looks a lot like a much older Janeane Garofalo. She's understandably alarmed at the suggestion that her son doesn't have schizophrenia, largely because that's what he's been treated for during the past seven years. Olivia asks if Sean has any siblings, and Mrs. Keenan says they only had one child. Lincoln diplomatically asks if it's possible that Sean's father could have had another child. Mrs. Keenan is all, his biological father? Well, sure. Turns out Sean was conceived through in-vitro fertilization, and they used a sperm donor. Oh, so there could be hundreds of half-siblings. Terrific! Olivia asks what she can tell them about the donor, and all Mrs. Keenan says is that he seemed impressive on paper. So instead they ask about the doctor, a Dr. Owen Frank, and Mrs. Keenan says he was referred to them by a friend who said he "only took the best donors" so that his results were better, which I'm sure is markedly different from other doctors who like to tout their average donors and middling results. But since we're taking time to note that the doctor promises just the best donors, we know it's going to turn out to just be him.
Anyway, Mrs. Keenan says that a reporter called and left a message a couple of days ago, doing some sort of piece on in-vitro fertilization. His name was Daniel. A reporter named Daniel? That this show kills off? I OBJECT! Olivia's all, "Daniel Greene?" and Mrs. Keenan says that's it. She called him back, but he never returned her call. She offers to go get her IVF file that she dug up after the reporter called. While she's gone, Lincoln (calling Fringe the "Department of Strange") and Olivia discuss the possibility that the children killed Greene -- and somewhat bafflingly, this is the first mention of the victim's name or occupation, which makes me wonder if there was an earlier scene cut from this episode -- because of the story he was writing. Lincoln says he'll contact the editors to see if they knew anything about his angle, or anybody else he may have interviewed.