After the commercials, Frank says, "Stand down. Lower your weapons." The "nurse" comes over and says, "What's going on here. This man's very ill." Frank asks authoritatively, "Is this man Steven Prescott?" The "nurse" snots, "No. His name is William Leverton. This is his house." Doe asks, "How long has he been like that?" Then he walks over to the man lying in the bed and gets right down into his face before asking, "Are you Steven Prescott? Do I look familiar to you?" Not "Did you kill Elizabeth" or "Did you kill Vanessa" but like little Baby Bird, Doe wanders around wondering, "Are you my father?" Please. So, Old Geezer Guy does his best impression of Darth Vader. The "nurse" snits, "What do you people want?" Well, considering they're the POLICE, they might be asking about a CRIME. Honestly, are the guns, shields, and badges really that confusing? Frank says, "I think we've made a huge mistake." Doe asks Vader, "Are we related?" Vader doesn't answer. He just looks around with his eyes and sort of semi-passes out. John goes to lift the oxygen mask from his face, and this triggers the same flashback he's been having all episode.
One woozy flashback later and Doe's in the car with Frank, who's going on about having your skivvies pulled down around your ankles or something. Does this guy ever talk in understandable sentences? John says, "Where are we?" This makes Frank very angry: "What?" Pause. "Is this some kind of game to you? Because we just came out of Leverton's five minutes ago." Pause. "I'm getting pretty tired of this." John insists he had another blackout. He pants. "I don't know what's happening to me." Frank cracks, "You're not getting enough oxygen to your brain." Oxygen? Oxygen. Oxygen! That's it! Sherlock Doe has cracked the case wide open. "Turn the car around! Leverton is Prescott. He's the killer." Frank looks unimpressed: "Really. Well, let me reassemble the tactical unit." Ah, sarcasm -- friend to all Type A cops. John blathers on about the oxygen tank; apparently, it was still on factory settings, which means he wasn't using it. Frank: "But what about Nurse Ratched?" Heh. Doe postulates that she was wearing a costume, and that she's Prescott's trophy wife. Frank complains, but he does reluctantly turn the car around.
But wait! When they get back to the mansion, Prescott/Leverton is gone. Frank screams, "Dammit!" John Doe looks through a desk in the bedroom as Frank continues, "He's got a ten-minute lead on us, maybe he's going to another residence --" Nope. Doe knows he's going to the airport. Is he a psychic now too? Nope. He smiles at Frank as he holds up a flight confirmation.