S4E3 · Teliko

On an international airline flight, an African man enters the bathroom, where he is attacked by a man exhibiting albino traits. The attacker leaves the bathroom with his normal black skin tone. Before the plane lands in the United States, a flight attendant discovers the victim in the bathroom, devoid of his skin pigmentation.

Three months later, Walter Skinner (Mitch Pileggi) calls in Dana Scully (Gillian Anderson) and informs her that four African American men have been kidnapped in Philadelphia. One of them has been found dead exhibiting depigmentation. A specialist from the CDC believes that the men have died from a disease, and has requested Scully to investigate the case. Fox Mulder (David Duchovny) joins Scully and has some of the evidence samples from Sanders' autopsy analyzed by Agent Pendrell, who finds a seed from a rare West African passionflower. Mulder takes the seed to his UN informant Marita Covarrubias and asks for her help; she provides him with information on the incident on the plane.

Meanwhile, Samuel Aboah (Willie Amakye), an African immigrant who is seeking citizenship, attacks a young black man while he is waiting for a bus, kidnapping him. Investigating the disappearance, Mulder predicts that another seed will be found. They have Marcus Duff (Carl Lumbly), a social worker who is helping Aboah apply for citizenship, cross-reference the names from the flight with those applying for permanent residency or a work visa. This leads them to Aboah, who runs when they try to question him and is discovered after squeezing himself into a drainage pipe. Aboah appears to have no symptoms of disease when he is analyzed at a local medical center, but Scully plans to examine him more.

Mulder sees Diabra, a diplomat from Burkina Faso. Diabra tells him an old folk tale of the Bambara people about the Teliko, which were nocturnal "spirits of the air". Meanwhile, Scully examines a PET scan of Aboah, which shows that he has no pituitary gland. Aboah escapes the hospital and meets Duff in a car; he paralyses Duff in the same manner as his other victims and inserts a long metal object up his nose. A policeman finds Duff and requests an ambulance, and the police tell Mulder and Scully that they are sweeping the area for Aboah. Driving around, Mulder tells Scully that he thinks Aboah is the mythical Teliko.

The agents stop at a demolition site after Mulder remembers that Pendrell found asbestos fibers on Sanders' body. After they split up, Mulder is paralyzed and taken into a duct by Aboah. Scully, having heard Mulder's shouts for help, tracks him in the duct and is able to get him out, finding the depigmented bodies of the other victims. Aboah gets the drop on Scully, but Mulder's look alerts her, and she quickly turns around and shoots him. In her field journal, Scully writes that Aboah is struggling to survive while awaiting trial. She muses that Aboah's condition and survival may be discovered by science, but humans have a fear of an alien among them which causes them to "deceive, inveigle, and obfuscate".