Episode opens in Pittsburgh, PA
If Leonard is able to regenerate entire parts of his body, whole fibres, and bone structures from scratch, why then, didn't he regenerate his hair?
When Scully shocks Betts with the defibrillator Betts is still on top of her this means she would have gotten shocked too. That's why medical staff yell "Clear!" before they shock a person.
When Scully finds out about Betts' mother she says that "she lives right here in Pittsburgh". Nothing wrong there except that at the time they has just left Chuck Burks' lab - which is in Maryland.
In the teaser Michelle seems genuinely surprised about Betts' diagnosis of the patient but in her talk with Mulder later, she makes it sound like it happened all the time.
Mulder: Chuck, would you believe that this man's head had been decapitated.
Dr. Burks: Oh come on. No way!
Mulder: Way! (to Scully) Are we happy with the results?
Mulder: Wouldn't it make sense that evolution or natural selection would incorporate cancer – the greatest health threat to our species as part of our genetic makeup?
Scully: Why do I think that Charles Darwin is rolling in his grave right now.
Mulder: What did your examination uncover?
Scully: Well, I... I haven't exactly performed an examination yet.
Mulder: Why not?
Scully: Well. Because I, uh … I experienced an unusual degree of postmortem galvanic response.
Mulder: The head moved.
Scully: It blinked at me. I mean, I... I know exactly what it is. It's residual electrical activity stored chemically in... in the dead cells.
Mulder: Blinked or winked?
Scully: What are we doing here?
Mulder: Did I mention that Mr. Betts had no head?
Scully: Yes, so? I mean, you're not suggesting that a headless body kicked his way out of a locked morgue freezer, are you?
Mulder: (Looking in morgue freezer) Pretty cozy. Who'd ever want to leave?
Scully: Well, whoever happened to get locked in here last night, I guess.
Mulder: That would be a Mr. Leonard Morris Betts, age 34. But it should probably be noted that when Mr. Betts arrived here last night he was sans head.
The dark liquid Betts submerges himself in while regenerating his head is identified by Mulder as providone iodine, which, he tells Scully, is used by researchers to promote limb regrowth in amphibians. It is widely sold and used in hospitals as a topical disinfectant under the brand name Betadine.
Although considered harmless to human skin, it was cited in a 1975 article in the Journal of Pharmaceutical Sciences as being capable of altering DNA in living cells and having mutagenic effects which could lead to cancer, which makes it ideal for Betts' purposes.
This episode had the highest rating in the show's nine-year run.
This episode aired after SUPER BOWL XXXI.
The name 'John Gillnitz' appears here again, as the name of the man in the bar. It is a combination of the names of the writers John Shiban, Vince Gilligan & Frank Spotnitz.
Betts is assigned to ambulance #208, and Scully wakes at 2:08am with a nosebleed; both possibly a reference to episode 2:08 'One Breath', where Scully is returned after her abduction.
The first indication of Scully's cancer arises in this episode when Betts says to her "I'm sorry, but you've got something I need".
Famous Catchphrase: "Will the real Leonard Betts please stand up?"
This is a line from a game show called To Tell The Truth, in which a biographical sketch was given for a contestant, who was presented along with two impostors. The trio was questioned by a panel of celebrities, who then tried to pick the real person. The denouement came when the host (Garry Moore in the original run of the show) said, "Will the real John or Jane Doe please stand up?" The first version ran from 1956 to 1968, and it was revived for runs from 1969 to 1978 (again hosted by Moore), 1980-1981 (hosted by Robin Ward), 1990-1991 (hosted by Alex Trebeck) and in 2000-2002 (hosted by John O'Hurley ).