The plot follows survivors of an accidental military gas leak involving an experimental agent that kills everyone on Earth over the age of 25 (a cartoon title sequence shows a John Wayne-esque Army General announcing — and denouncing — the "accident"; the story picks up as the last of the victims are dying with social commentary on Medicare and Medicaid).

The subtitle alludes to the 1968 quote "it became necessary to destroy the town to save it" attributed to a U.S. Army officer after the Battle of Bến Tre in Vietnam.

Robert Corff and Elaine Giftos star, with Ben Vereen, Cindy Williams, Bud Cort, and Talia Shire (credited as "Tally Coppola") in early roles.

Country Joe McDonald, who provides the music, makes an appearance as a spokesman for "AM Radio".

[2] In Dallas, at Southern Methodist University, news comes in about a gas which has escaped from a military facility.

Coel and Cilla then meet music fan Marissa, her boyfriend Carlos, a man called Hooper and his girlfriend Coralee.

The group meet Edgar Allan Poe, who throughout the film drives around on a motorbike with Lenore on the back and a raven on his shoulder, commenting on the action like a Greek chorus.

The group then have an encounter with some golf-playing bikers, after which they attend a dance and concert where AM Radio is performing and passing on messages from God.

Coel, Cilla and their friends arrive at a peaceful commune at a pueblo where it seems mankind can start fresh.

George Armitage had met Corman at 20th Century Fox when the latter was making The St Valentine's Day Massacre.

"[3] Corman said that although "there was some good work in" Armitage's first draft, "the points I was trying to make in the script either did not come through or came through too obviously different parts, and it became less science fiction and more and more a direct liberal left-wing statement picture.

So I then decided to switch to a comedy, thinking back to Bucket of Blood and Little Shop of Horrors.

To wait till next summer would have dated the material I was dealing with, so I wanted to bring the film out early.

"[4] Stephanie Rothman had been Corman's assistant in the mid-60s but taken a sabbatical from the industry after making her directorial debut with It's a Bikini World.

She went back to work with Corman on Gas-s-s-s as a production manager along with her husband Charles Swartz.

I intended that the picture be sympathetic toward our lead gang of kids yet, at the same time, I wanted to show that I was beginning to suspect that all of the ideas being spouted by the counter-culture and all of the dreams were not totally rooted in reality.

He later wrote in his memoirs: I ended the film with a spectacular shot from on top of the mesa, with a view sixty, seventy miles to the horizon ... God, who was a running character throughout the film, made his final comments on what went on...There must have been three hundred people on top of that mesa.

The more irreverent the film, the greater the financial risk...Jim [Nicholson] had grown conservative and it was his objections to my work that led to the cuts.

[2]Corman elaborated, saying: [God was] played by an actor with an outrageous New York Jewish accent and they were really startled by that.

I think it was partially the fact that AIP had become a public company and Sam [Arkoff] was Jewish and they didn't want to be accused of being anti-Semitic.

[8]However, Samuel Z. Arkoff of AIP recalled it differently: When Roger left for Europe to shoot Von Richthofen and Brown for United Artists, he turned over the rough cut to us.

They also cut out a final shot that Roger adored, in which he positioned the leading man, his lady, and three hundred extras on a mesa...The camera panned back while the words of God were heard in a voice-over.

Since it's a very inexpensive picture, they've been playing it around the country in drive-ins and small towns where it's been doing only moderate business.

[4]According to Samuel Z. Arkoff, "when Gas-s-s-s was released, it was promoted with ads that proclaimed, 'Invite a few friends over to watch the end of the world.'

I didn't want at any time to allow the preachings of what I was saying to come across too heavily and disturb the flow of the picture and its humor.

Filmink argued "the film’s a mess, to be told, but often funny and fascinating for Corman watchers because it summarises so much of his career until that date: there’s references to Westerns, Edgar Allan Poe, the apocalypse, sex, progressive politics, bikers, race relations, rape.