The show centers on FBI special agents Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) who work on cases linked to the paranormal, called X-Files.

In this episode, Mulder and Scully, while traveling to a conference with two other FBI agents, stop at a roadblock and join a nearby investigation of attacks by an unidentified predator.

Executive producer Frank Spotnitz was inspired to write the episode after watching the 1972 American thriller film Deliverance.

Two men are surveying an area of the Apalachicola National Forest in Leon County, Florida when they are attacked and killed by unseen assailants with glowing red eyes.

Meanwhile, Fox Mulder (David Duchovny) and Dana Scully (Gillian Anderson) are carpooling with FBI agents Michael Kinsley and Carla Stonecypher en route to a "team building" seminar.

When they are stopped at a roadblock by local police, Mulder decides to investigate, in part to get away from Kinsley and Stonecypher, whose perky nature annoys him.

As he and Scully venture into the woods, they are informed by Officer Michele Fazekas that no conclusive evidence has been found to support Louis' report of a shooting.

Jeff Glaser, a local technician armed with a FLIR device, joins Fazekas, Mulder, and Scully to search the woods for the creature.

The next morning, Scully falls through a hole in the ground while foraging for food and finds herself in an underground chamber where the bodies of the missing people are being stored.

Afterwards, Mulder realizes that the creatures presume others' presence in their territory as threatening and rushes to the hotel room where Scully is packing her things.

"[3] When the script was undergoing a rewrite, series writer Vince Gilligan helped by proposing a few story elements, including Mulder and Scully partaking in a "team builder" exercise.

Because of the massive delays, changes were made: the actors' schedules were adjusted, Kim Manners was brought in to assist Dowler, and filming later moved to a soundstage to avoid the incessant rain.

[2] The plot and nature of the episode resemble the film Predator (1987), in which a creature that is able to perfectly camouflage itself, almost to the point of complete invisibility, stalks several humans in a dense jungle.

[4] While camping in the woods overnight, Scully sings "Joy to the World" by Three Dog Night while Mulder rests so that he can know she is awake and on guard.

The site called the sequence wherein "Scully holds a wounded Mulder and sings 'Jeremiah was a Bullfrog' [sic]" the "best scene" of the episode and praised the depth of the characters' relationship.

[6] Jonathan Dunn, writing for What Culture, highlighted "Detour" for its cinematic appeal and included it in the "5 Episodes [of The X-Files] That Could Be Made Into Movies" list.

[4] She called the scene featuring Scully singing to Mulder "a failed attempt to create 'a special X-Files moment'" and noted that the sequence was "a poor substitute for meaningful dialogue".

[4] Robert Shearman and Lars Pearson, in their book Wanting to Believe: A Critical Guide to The X-Files, Millennium & The Lone Gunmen, rated the episode two stars out of five.