Director: Kim Manners
When Emergency Medical Technician Leonard Betts is decapitated in a road traffic accident involving his ambulance and a truck on the streets of Philadelphia, his headless corpse disappears from the Monongahela Medical Centre. Mulder and Scully are brought in to investigate the disappearance of his body. Scully believes that someone took the corpse to sell to an unscrupulous medical supplier. But security camera footage appears to show Leonard Betts' body with a distortion around the head walking out of the hospital.
They find Leonard Betts' head in the hospital's bio-disposal unit and Scully performs an autopsy on it, during which the eyes suddenly open. After tissue samples from the head reveal it was riddled with cancer, so much so that Leonard Betts should have been dead long before he was decapitated. Mulder begins to theorise that Leonard Betts could be mankind's next evolutionary step, some how incorporating cancer in to his body structure giving him amazing regenerative capabilities. Scully marvels at Mulder's theory that Leonard Betts has simply grown a new head.
However evidence emerges that Leonard Betts is indeed whole again and working at another hospital, further evidence seems to indicate that he is ingesting cancerous tissue, that his job gives him ready access to, in order to survive. As the agents close in on Leonard Betts, he has to find other sources of cancerous tissue, he targets Scully explaining that she has something he needs.
Betts is assigned to ambulance #208, and Scully wakes at 2:08am with a nosebleed; both possibly a reference to episode 2X08 ''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".
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.
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: (on phone) Mulder, it's me. We've got Mrs. Tanner going into the ER, but she took a downturn en route. They defibrillated herto try and get her to try and get her heart back, but there's no chanceof getting anything cogent from her. Not tonight, anyway. Whatabout on your end?
Mulder: (on phone) We're going house-to-house, here. That's the only thing I can think to do. We got a chopper coming in, but until then I'd say Betts has got a pretty good chance of getting away.If he steals a car or gets a ride, he could get away for good.
(Scully notices dark fluid has dripped onto her head from top ofambulance.)
Mulder: (on phone) I mean, he obviously worked this thing out pretty well, Scully, so if there's anything you can get out of Mrs.Tanner tonight, anything at all, at this point we don't have much elseto go on.
Scully: (on phone) Mulder, get over here right now.
Mulder: (on phone) What?
Scully: (on phone) Get over here now.
(Scully draws her gun and climbs up ladder on side of ambulance tolook on top. Leonard Betts grabs her foot and pushes her in the vehicle.)
Betts: I'm sorry … but you've got something I need.