Visible crew/equipment: When the Lone Gunmen catch up with Suzanne at the end of the episode, when she is talking to them and the camera is on the three, you can see not one, but two boom mics at the top of the screen.

Continuity: The toxicology report lists the birth date of Mrs. Sim as 6/6/67 which would make her 30, but Detective Kresge says that she is 40 years of age.

Continuity: Scully's FBI badge number that she gives to the phone company is different to the one she gives in season 4's "Teliko".

Continuity: Mulder says that Scully was abducted and missing for four weeks. In "Duane Barry," the date stamp is given as August, then in "3," when Mulder returns to the X-Files office he turns the calendar all the way to November. Since Scully is returned the next episode after this, she must have been missing for at least 3 months, not 1.

Continuity: How was Modell tried and convicted in 1996 if he only woke up six months ago? Six months before this episode would be at least mid 1997.

Continuity: After her father is pulled out of the window, Lisa leans out and there is no glass left on the sill, she even places her hands on it. Later when Mulder and Scully look at it, there is all sorts of jagged edges on the sill.

Continuity: In the same season episode "Unusual Supects" Fox Mulder's file lists him as Fox William Mulder. The A.I. discovers a similar file but the name is just Fox Mulder.

Visible crew/equipment: I don't know if this is visible in all formats, but on the newest UK release on DVD, watching in widescreen, it's amazingly obvious. When Mulder recovers from the vampire attack, he gets up from the floor and breaks up a chair to make a stake. There is a shot of his feet as he smashes the legs off and bends to pick up a piece. In the bottom left hand corner of the screen, you can see a crew member's hand carefully and quickly placing a piece of wood on top of the pile for Mulder to pick up.

Revealing: When the doctor examine Ronnie's "corpse" in the morgue, he pulls out the stake. It is quite obvious that he's struggling with a wooden stake that is placed on the actor's side, not through his chest. Moreover, the camera pans up and you can briefly see Ronnie's unharmed chest.

Visible crew/equipment: During the scene where Mulder is breaking the chair in his hotel room to create a stake, a hand comes out from the left to place a stick on the ground that Mulder immediately picks up.

Continuity: In season 2's "Ascension," Skyland Mountain was a private ski resort, yet here we are told it is a national park.

Other: When Marty is being transferred and 'sees' herself because the killer is watching her, she should have seen herself viewed through a wire fence, as the killer was standing behind one.

Continuity: At the end of this episode when Mulder is talking to Marty through her jail cell, the position of their hands change. In one shot, Mulder's hand is covering hers, and in the next, each of their hands are gripping the cell bars. This goes back and forth a few times.

Revealing: During the autopsy, right after Scully has the vision of her daughter, the body of Paula Koklos can be seen to move (watch her hands and neck).

Continuity: If the Kernoffs were really devoted Catholics why would they have waited six years to have Dara baptised?

Continuity: When the bank manager goes to open the door for the brinks truck containing the robbers, the clock on the wall reads 9:45. When the robbers are taking him back to the vault, a couple of shots of the skull-masked robber shows the clock reading about 9:43.

Continuity: A move is repeated in the opening chess game. The first overhead shot shows Gibson's white rook near the top left of the board. The adult opponent then takes it with his king at the bottom of the board. Gibson next moves the white rook to the bottom of the board and the adult captures it again, repeating his earlier move.

Continuity: In addition, to the repeated move, a black pawn suddenly moves backward one space, which is not only a continuity error but an impossible move. Without this change, Gibson would not have gotten checkmate as the black queen would have not have been blocked.

Continuity: When we see the Russian guy get shot and he falls out of his chair, he knocks the chessboard off the table. But when Jeffrey Spender shows his team the tape, the guy hits the board so that it spins around, instead of falling off completely.