The episode opens in an art class, where a nude male model is being sketched. One student, visibly disturbed, scrawls what appears to be a goblin instead. He cuts his finger sharpening his pencil and gets blood on the drawing. The artist is very agitated as the class ends and he leaves. The model also leaves, and finds a pencil jammed into the lock of his car door. Suddenly, someone attacks him with a utility knife. The next morning, an FBI task force bursts into the artist's apartment and arrests him; in the process he bites one of the agents, Nemhauser, on the hand. The art on his walls reveals a man obsessed with demonic creatures. Task force leader Bill Patterson searches the man's toolbox and discovers a utility knife with blood on the blade.Mulder and Scully discuss the M.O. of the artist, Russian emigre John Mostow, who has allegedly killed seven young men. He attacks and badly mutilates their faces, resulting in death from massive blood loss. Skinner has assigned them to the case because Mostow, despite his history of involuntary commitment back in Russia, is claiming he was possessed by a demonic entity when he committed the murders. This is what Mostow maintains when the agents visit him in prison. He has drawn the gargoyle on the floor of his cell, professing that it drove him to commit the murders, and is continuing to do so even after his imprisonment. The questioning is interrupted by the arrival of Patterson and Nemhauser. Patterson, who has spent three years working on this case, believes an accomplice has taken up where Mostow left off; Mulder is skeptical, especially since Patterson's own profile indicates Mostow acted alone. The conversation between Mulder and Patterson is tense; as they leave, Mulder tells Scully that Patterson acted as a mentor when Mulder studied under him at Quantico's Investigative Support Unit, but they had a falling out when he did not idolize Patterson and his gift for profiling the way others did. He does, however, recall one of Patterson's primary lessons: "To understand an artist, you have to study his art."
Searching Mostow's apartment, Mulder and Scully discover a concealed passageway leading into a hidden room. It is filled with life-size clay gargoyles, but upon closer inspection, Mulder finds they are clay shells over human bodies. Five are found in all; young men whose faces were mutilated like the previous victims.
A glass blower is attacked and badly wounded. At the hospital, Nemhauser tells Scully that, despite his outward enmity, Patterson respects and possibly even admires Mulder's profiling abilities. He also implies that Patterson requested Mulder and Scully be assigned to the case. When Patterson himself shows up, Scully informs him that Mulder is looking into the gargoyle aspect. Patterson is annoyed, continuing to believe in the accomplice theory.Patterson finds Mulder in the library studying gargoyles, which are meant to protect against evil spirits. Believing Mulder is wasting his time, Patterson expresses disappointment in him. Scully goes to Mulder's apartment and finds it covered with gargoyle drawings. Mulder studies the drawings in Mostow's apartment and begins sculpting a gargoyle himself. He falls asleep and is awakened by someone with a gargoyle's head staring down at him. Mulder gives chase but is attacked by the figure, who slashes his face with a utility knife.
Scully is peeved to learn that Mulder was in Mostow's apartment at 3:30 A.M., and she defaults to her usual rational explanation of the murders. Mulder ignores her and leaves. Scully challenges Patterson, who claims that he brought Mulder on the case not because he is trying to humiliate him, but because he thinks only Mulder can solve it. He also warns her not to try and hold Mulder back, "because you won't be able to." As Scully leaves the scene she finds a disassembled utility knife beneath a police car.
Mulder consults Mostow in prison to find out why he wasn't killed. When Mostow refuses to talk Mulder strikes him, but still learns nothing. Mostow says that anyone could be possessed by the gargoyle, even Mulder; maybe, based on his reaction, he already is. At the crime lab, Scully learns that the fingerprints on the knife blade are Mulder's. Scully visits the evidence warehouse; as she is called to meet with Skinner, she discovers that the utility knife Mostow used is missing. Both she and Skinner express concern about Mulder's bizarre behavior.Mulder has a dream where he is attacked by the gargoyle, which is revealed to be himself. Awakening, he returns to Mostow's studio to find a new gargoyle sculpture. Finding a trail of blood on the floor, he follows it to a severed arm. He also finds a cellular phone in a coat, which starts ringing. It turns out to be Scully, who is calling Nemhauser's phone in response to a message he left saying he had to tell her something. She wants to know why Mulder went to the evidence room and handled the murder weapon himself, leaving his prints on it. He tells her he wanted to know how it felt to hold the knife, and that he doesn't know where Nemhauser is. Scully tells him she's coming over. Mulder goes to the new sculpture and tears it apart to find Nemhauser, his face slashed open and his body dismembered.
Patterson appears. Mulder accuses him of being the murderer, having seen that his hands are covered in clay. Patterson's technique of identifying with the murderer has gone too far, presumably allowing him to be possessed by the demonic entity that plagued Mostow and leading him to continue the murders; he killed Nemhauser when things started to point to him. Mulder holds Patterson at gunpoint, but Scully arrives and draws the wrong conclusion. Patterson flees; after a chase and struggle he is shot by Mulder and arrested.
Patterson is jailed for the murders, and is last seen pressing against the bars of his cell, desperately claiming to be innocent. Behind him is another gargoyle face that he has etched with soot and his own blood. In voiceover, Mulder laments the fact that when men like Patterson, whose job it is to enter the minds of killers, look into the abyss for too long, sometimes the abyss looks back, and brings out their own demons.
- This episode and the Season 2 episode "Irresistible" are often cited as the "roots" of Chris Carter's companion show to The X-Files, Millennium.
- Mitch Pileggi and Kurtwood Smith later appeared together in a Season 1 episode of That 70s Show, where the two were old war buddies.
- To prepare himself for this episode, director Kim Manners listened to the soundtrack of "Jacob's Ladder" over and over again, much to the chagrin of his wife.
- Agent Nemhauser is named after X-Files Post Production Supervisor Lori Jo Nemhauser.
- The concept of a man coating human corpses with clay to make sculptures was used prominently in the 1959 Roger Corman film, A Bucket of Blood, written by the late Charles B. Griffith.
- "Gargoyle" comes from the French gargouille, which refers to the throat. Gargoyles are carved figures that cover up drain spouts and make a gargling sound as water flows out of their mouths.
As the medic says "You're all set," the butterfly bandages on Mulder's eyes are set so one is pointed upward and the other is pointed to the top of his ear (24:06), but when Scully mentions his new "wallpaper" the bandages are set different, they are slightly overlapped and both are now pointing the same way (25:01).
When Scully and Mulder first visit Mostow, he says that he drew the gargoyle picture in his cell, which would have been a pretty good act considering he was in a strait jacket and would not have been allowed to have drawing materials anyway.
Mulder tells Scully that he came to work with Patterson at the Investigative Support Unit just after he left the FBI training academy. This seems to contradict Season 1's "Young at Heart", in which Mulder joined the Violent Crimes Section under Reggie Purdue after leaving the academy; Mulder even mentions in "Young at Heart" that the John Barnett case was his first at the Bureau.
BookA young adult novelization of the episode was written by Ellen Steiber, who also penned adaptations of Squeeze, Shapes, Eve, Oubliette (retitled Empathy), Hell Money (retitled Hungry Ghosts), and Shadows (retitled Haunted). Like most other X-Files books, it stays fairly close to the plot of the episode; a lot of the dialogue is almost verbatim. The book's main alteration is to have Scully and Mulder present in the final scene at the prison.