Dexter Sheriff informs Doggett and Scully that the blood on the knife was Billy's, although Billy himself was not cut in the melee. He laconically explains that Mr. Underwood has never seen that knife before, and that he (Mr. Underwood) is not a hunter, and has no dead animals lying around, needing cleaning. "That's all this knife is good for," Dexter Sheriff drawls, "'cept killing, o' course." Scully looks like her head hurts. Join the club, sweetcheeks. She wonders if Billy ought to be institutionalized. Doggett doesn't think that's a good idea, telling her that Billy is just a kid, who's been through a lot. That's, like, the understatement of the year, as I think dying is the dictionary definition of "going through lot." Oops, did I just give away the ending? Sorry. Scully rolls her eyes and points out that jamming bloody hunting knives into the mattresses of siblings isn't normal behavior. Doggett tells her that she's acting like Billy is possessed. "Call the exorcist," he snarks. She rolls her eyes again. Um, just as a sidebar, as a policeman, wouldn't Doggett have seen that, sometimes, children are capable of violence? Or is that just on Law and Order? Doggett pleads with Scully to "give [Billy] a chance. He may be trying to communicate." Yeah, he's trying to communicate that he's eeeevil. Scully snaps that, in case Doggett has forgotten, Billy may be a child, but he's also a child who has reappeared out of nowhere and hasn't aged in ten years, and, dude, that's so not normal. Doggett fingers the knife, and notices a symbol carved into the handle; lo and behold, it's the same Blair Witch Project symbol that Billy was drawing earlier. He asks the sheriff about it, and the sheriff stammers that, ten years ago, when the case broke, the police department brought in a psychic to help them find Billy, and that symbol was the only thing she came up with. Doggett stares at the knife, as Scully stomps over to the table and picks up Billy's drawings -- a paper covered with the self-same symbol. I wonder if that's supposed to be a clue, or something? She gives Doggett a big old "I told you so, sucker" look.
Back at the Underwood compound, Mrs. Underwood is buttoning Billy's shirt and telling him how much she loves him, and that she wants to put "whatever happened" behind them, to be a family again. She asks him to help her understand what happened. Billy stares. Mrs. Underwood scoops him up and tells him that they're taking him to a doctor, someone he can talk to. She promises that she won't ever let anything bad happen to him ever again.