S3E7 · The Walk

At a VA hospital in Fort Evanston, Maryland, Lieutenant Colonel Victor Stans makes his third suicide attempt; he claims that a mysterious figure will not let him die. Stans attempts to drown in a tub of scalding water, but is rescued by the hospital staff and left disfigured.

When Fox Mulder and Dana Scully question Stans, they learn that his wife and children died in a house fire he claims was started by the mysterious soldier he says will not allow him to die. Captain Janet Draper stops the questioning, as Mulder and Scully were not granted permission to see Stans by his superior officer, General Thomas Callahan. After meeting with the agents, Callahan glimpses the phantom soldier Stans described. He also finds his answering machine replaying an unintelligible message. Later, while using the base's swimming pool, Draper is drowned by an invisible force.

Callahan tells the agents about the soldier and the voicemail, which was received twice before at his home. When they visit his house, his young son, Trevor, believes he saw someone go inside; Scully herself glimpses someone in the backyard. Fingerprints are found on the property which belong to the hospital mailman, Quinton "Roach" Freely. As Mulder and Scully take Roach into custody, Trevor is attacked and buried by the invisible force in his sandbox. Under the agent's questioning, Roach admits to his role in the deaths and states he is "Rappo's mailman".

"Rappo" turns out to be Leonard Trimble, a Gulf War veteran and quadruple amputee. Scully doesn't believe Roach, even though he insists that Rappo will kill him next. Scully later finds Roach dead in his cell with a bedsheet shoved down his throat. Scully assumes that he committed suicide, but Mulder shows her X-ray film he carried in the rehab room, the pool, Callahan's office, and Callahan's house; all show signs of radiation. Mulder thinks that Rappo is leaving his body through astral projection, doing so with a psychic connection forged through Roach's letters. He plays the voicemail backwards; it is actually a threat from the phantom soldier.

Under questioning, an embittered Rappo blames his Gulf War experiences for ruining his life. Meanwhile, Callahan finds his wife's dead body. He goes to the hospital to talk to Stans, who reveals that Rappo — whom he doesn't know — is responsible for the deaths. When Callahan confronts Rappo, he openly admits his crimes. Rappo tries to goad Callahan into killing him, but Callahan decides to "stand down" and shoots over Rappo's head. Callahan tells Rappo that he will suffer like him and the others, leaving Rappo enraged. The agents arrive and find Rappo in a trance.

Scully thinks he's having a seizure, but Mulder realizes what is happening and tries to find Callahan. Rappo's apparition attacks Callahan with steam from the pipes in the hospital's basement. Stans enters Rappo's room, locks the door, and smothers Rappo with a pillow. With Rappo dead, his apparition disappears before it attacks Mulder. Callahan remains unharmed.

Since there is no physical evidence to prove that Rappo killed Callahan's wife and son, the case remains unsolved. Stans is released and becomes Callahan's mailman - both Lieutenant Colonel and General acknowledge each other before the former leaves to continue his work. Mulder's narration states that Rappo's family tried to have him buried at Arlington National Cemetery, but the Army denied their request; he was instead cremated and buried in a civilian cemetery in Pennsylvania.