"Signs and Wonders" earned a Nielsen household rating of 8.5, being watched by 13.86 million people in its initial broadcast.

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 Blessing, Tennessee, Jared Chirp, while attempting to flee his home, is attacked by rattlesnakes inside his car and killed.

When she is alone with him in his hospital room, O'Connor's wounds begin to spontaneously expel the venom, and he regains consciousness, takes Gracie, and flees.

After Mulder and Scully find test results at Jared Chirp's house revealing that he was infertile, Reverend Mackey tells them that Enoch O'Connor is the father of Gracie's child.

He confronts Mackey, but the demonic pastor telekinetically locks the door and summons snakes, which promptly attack Mulder.

[1] "Signs and Wonders" was written by The X-Files staff writer Jeffrey Bell, who had long wanted to write a "down-and-dirty" horror story for the series.

[2] Diverging from most stories that involve extremist religious sects, the main theme of "Signs and Wonders" is that in certain circumstances, "intolerance can be good", per executive producer Frank Spotnitz.

"[2] During the snake handling scene at the Church of God with Signs and Wonders, the song being sung by the congregation is called "May Glory Protect Us".

The song was written by executive producer Paul Rabwin, who was heavily involved in the episode's music production.

In order to prevent ophidiophobia from affecting the actors on the day of filming, live rattlesnakes were brought in during the casting sessions.

A false stomach was created for Tracy Middendorf, who portrayed Gracie, to give the illusion that live snakes were wriggling inside of her.

[3] At one point in the episode, Expulsion from the Garden of Eden, a famous painting by Italian Early Renaissance artist Masaccio appears in the background.

[6] Paul Rabwin later noted that "the network executive censors didn't feel it was appropriate for us to show all the details ... [of] course, they could see people giving birth to hundreds of snakes ... That's OK."[6] On the seventh season DVD special features, the painting is erroneously attributed to the famed Michelangelo.

Although a bit overly reliant on the alleged shock value of snakes, the episode establishes, more firmly than any before it, the demonic nature of some of the powers at work in The X-Files.

Robert Shearman and Lars Pearson, in their book Wanting to Believe: A Critical Guide to The X-Files, Millennium & The Lone Gunmen, rated it two-and-a-half stars out of five.

The two noted that, despite several very "cool" images—such as Gracie birthing snakes and a man oozing reptile venom—the episode "doesn't really seem to stand for anything.

"[12] Shearman and Pearson further criticized putting "religion in the crosshair" and concluded that the episode was "just your everyday sliver of supernatural hokum.

[15] Despite writing that the snake attack scenes were "surprisingly horrifying" and that the episode contained "plenty [of elements] to recommend", she was critical about the lack of explanation behind Mackey.