Scully finds a disassembled utility knife at the latest crime scene with Mulder's prints on it and discovers that the murder weapon is missing from the evidence room. She meets with Assistant Director Walter Skinner (Mitch Pileggi), who is also worried about Mulder's behavior. Mulder has a nightmare about being attacked by a gargoyle that is really himself. He wakes up and goes to Mostow's studio again, finding a severed arm. Scully gets a message to call Nemhauser, but his phone is answered by Mulder, who denies taking the knife. Mulder searches Mostow's studio and finds Nemhauser's body inside a new sculpture. Mulder is then confronted by Patterson, who is unaware of how he arrived at the studio. Mulder then deduces that Patterson is the killer, based on his three-year obsession with Mostow and his request for Mulder to investigate the case. Mulder confronts him, but Patterson flees when Scully arrives. Mulder pursues him and they fight, but Mulder perceives Patterson as a demonic gargoyle creature. Patterson is shot and apprehended.