But then, ominously - and this is in the trailer - they come to realize that their sleepy burg has changed. People are robotic, strange. Soon a legion of, well, whatever they are is chasing Pegg and his crew, eye sockets and open maws emitting beams of light.
And some kind of giant, alienlike sculpture has sprung to life.
Wright, for his part, defends the trailers.
"I think people talk about trailer spoilers a lot, as if it's something that's a new phenomenon, but I feel like it's been the same for decades," says the keen-eyed, bearded Brit.
"If you look at the trailer for Dirty Harry, or Carrie, or even the trailer for Psycho . . . you know, Hitchcock pretty much tells you there's going to be a murder in the shower. You know something really bad is going to happen."
Pegg says that it doesn't matter that people go into theaters knowing that there's a "sci-fi element" to The World's End. There are still plenty of head-spinning shocks to come.
"The truth of it is, if you did a trailer that was just taken from the first 30 minutes, it would look like a Mike Leigh film," he says, referring to his countryman who makes those miserablist masterpieces about working-class types struggling with monetary and marital woes. "You might hoodwink some people, but fans of genre films might not go at all."
As it turns out, Pegg is a huge Mike Leigh fan - hence the casting of Marsan, a Leigh regular.
"We're obviously big British comedy fans, all manner of British comedy, whether it's Python, or whomever, and there have been American comedies that have been a big influence on us," says Wright, who wrote The World's End with Pegg.
"But I think definitely the influence of Mike Leigh and Ken Loach can be felt . . . . And it was our idea to mix some of that naturalism in the performances with the extremely surreal and graphic craziness."
The World's End, which opened Friday, is the final installment in Wright's so-called Three Flavours Cornetto Trilogy, a jokey but earnestly cineastic nod to art-house god Krzysztof Kieslowski'sThree Colors Trilogy - and to the gag that runs through Shaun of the Dead, Hot Fuzz and now The World's End. The famous frozen ice cream cone appears in each.
Mike Leigh, Ken Loach, Krzysztof Kieslowski - is Wright a closet auteur? Are his sharp, screwball genre sendups really trying to say something?
"You can make an extremely mainstream comedy and you can make an audience laugh for 100 minutes," he says, "but most of them have forgotten it by the time they validate their parking.
". . . And what we want to do with these films - they do have some darker moments, or at least honest moments. They're a bit more raw than what you would find in a more typical man-child comedy from Hollywood.
". . . There's no other reason to make these films if we can't make them personal. We're not doing the films because we think we ought to, it's because we want to. And so outside of the comedy and the sci-fi and the pratfalls and the head-smashing and the fight scenes, hopefully there are real characters that people will recognize, or recognize themselves in the characters, and actually make them think about certain issues and themes."
"Saints" and Salander. In Ain't Them Bodies Saints, Rooney Mara plays a Texas girl who falls in with an outlaw. Early on, the couple hole up in a shack, the sheriffs closing in. Later, the outlaw - Casey Affleck - is sent to prison. He writes letters. She wallows and wanders, caring for the baby girl he left behind.
There are plaintive voiceovers and shots that catch the flare of the sun. The crickets creak and the trees whoosh. Terrence Malick, right?
Wrong. The filmmaker is David Lowery.
"I definitely can see the similarities that other people see, they definitely have a similar aesthetic and romanticism, and they're, you know, poetic," says Mara, on the phone from New York. The film opened Friday at the Ritz Bourse. "But I think they couldn't be more different as directors," she adds, having gone straight from Lowery's project to a new, still-untitled Malick film.
"The Malick of today is very different. And I don't think David set out to make this 'Malickesque' film. Badlands is definitely an inspiration . . . but there are many others."
Mara turned heads with her Mark Zuckerberg breakup scene in The Social Network, and nabbed an Academy Award best actress nomination for her performance as The Girl with the Dragon Tattoo. That was planned as the first installment in a trilogy based on the Stieg Larsson books, but while the intense David Fincher thriller, released on Christmas 2011, made money, it didn't hit the kind of numbers that immediately green-light a sequel.
Mara says she's eager to continue with the role of gloomy genius bisexual cyber-sleuth Lisbeth Salander.
"I hope we do it, but I don't know. I wish someone would tell me . . . . I'm here. I'm ready. And I would love to do that."
Have there been any signs that The Girl Who Kicked the Hornet's Nest is moving ahead?
"I don't know," she says with a frustrated laugh. "And I don't know what I'm allowed to say, or not . . . . But I think that they will do it. I really do.
"I just hope that they do it sooner rather than later, because I am not getting any younger."
Contact movie critic Steven Rea at 215-854-5629 or firstname.lastname@example.org, or follow on Twitter @Steven_Rea. Read his blog, "On Movies Online," at www.inquirer.com/onmovies