Plot (Spoilers):

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 subsequently is disfigured due to the hot water.

When Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) 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 himself. 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 killed 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 killed 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 (Ian Tracey), 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 dental plates he had 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 also plays the voicemail backwards; it is actually a warning from the phantom soldier.

Under questioning, an embittered Rappo states his belief that the Gulf War took his life away. 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," shooting over Rappo's head. The agents arrive and find Rappo in a trance; 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. Mulder's narration states that Rappo's family tries to have him buried at Arlington National Cemetery; he is instead buried in a civilian cemetery in Pennsylvania.

Production

"The Walk" is the first X-Files script by John Shiban. He found it challenging to write, particularly Mulder and Scully's first scene where "they have to come together on a case, yet they have to be at odds". Shiban was inspired by the film The Men and realizing that the main character, who had been injured in war and lost his legs, wanted to walk more than anything. He stated that the paranormal concept of astral projection "just sort of fit". Some members of the writing staff were concerned about killing Callahan's young son, Trevor,