The show centers on FBI special agents who work on cases linked to the paranormal, called X-Files; this season focuses on the investigations of John Doggett (Robert Patrick), Monica Reyes (Annabeth Gish), and Dana Scully (Gillian Anderson).

In this episode, Reyes and her fellow agents investigate a serial killer who uses numerology to choose his victims.

The tagline for this episode is "Dio Ti Ama", meaning "God loves you" in Italian, replacing the usual phrase "The Truth is Out There."

Agent Monica Reyes (Annabeth Gish) is investigating the woman's murder as the latest in a series of cases that she believes are linked by numerology.

While explaining the case to Dana Scully (Gillian Anderson), who rejects the idea that numerology is relevant or that the world can be broken down into one simple equation, Scully discovers another possible clue—marks on each of the victim's cheeks that looks like three small circles, likely imprinted by the killer's ring while he beat the victims.

Reyes' numerology theories do not go down well at the FBI, but the pattern of the killings, when viewed on a map, seem to line up as the number six (6).

Scully recognizes the ring on the killer's hand as the agents exit the elevator, and draws her gun on him.

Reyes eventually realizes that the checkers' colors (red & black) are surrogates for Scully (a redhead) and herself (a brunette); The pair realize that the last victim, the numerologist (victim number 7) was a blonde, and that the murderer has been following a pattern of killing a blonde, then a redhead, then a brunette.

However, John Doggett (Robert Patrick), also realizing that the number "6" pattern is actually a "9" and that the killer must intend to have two more victims, arrives in the nick of time to shoot him.

Two men sing a comical and upbeat song (Io Mammeta E Tu) in Corsican and lead a crowd through the streets.

The camera zooms out to reveal that the entire neighborhood, when viewed from above, suggests the appearance of Burt's face, hinting at the fact that he might be God.

"[3] The use of numbers in this episode helped emphasize the idea "that numerology is an important part of our life and plays a part, but it really ... illustrate[s] the idea of patterns, patterns of behavior, of the ways in which numbers rule both the universe and our lives and our ability to solve things, [and] to solve our mysteries of life".

[4] The tagline for this episode is "Dio Ti Ama", meaning "God loves you" in Italian, replacing the usual phrase "The Truth is Out There."

Before casting Ellen Greene, Carter had first spotted her in the musical, Little Shop of Horrors both in "New York and Los Angeles."

"[3] Burt Reynolds was chosen for "Improbable" after he expressed his desire to appear in an episode of The X-Files to Robert Patrick.

"[3] The final scene, featuring Burt's face superimposed onto the cityscape, was created by special effects supervisor Mat Beck.

Snow based much of the music in the episode on records made by Karl Zéro, on the request of Carter.

Because of his situation, he "acts on his bad impulses"; Carter elaborated, "Is it fate that Wayne is about, the character, this is what I was interested in exploring here.

[2] 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 four stars out of five, and called the script "very witty".

[11] The two wrote that "the brilliance of Chris Carter's direction" allowed the viewer of the episode to see it "from God's point of view".

Burt as one of the "Top 11 X-Files Monsters", noting that "as [series creator Chris Carter] imagines him, [God] is a benevolent deity, constantly prodding his creatures to look at the patterns before them, to see the overall plan that he's laid out.