Are you ready for “Contagion”?

In a year that has seen its share of troubles, Warner Brothers will soon open a film that is sure to expand the pool of worry and scare moviegoers into seeing that guy with a persistent cough in the next seat as, just possibly, the beginning of the end.

“Contagion,” directed by Steven Soderbergh, is to be released on Sept. 9 — the 10th-anniversary weekend of 9/11 . In the style of his drug-wars drama from 2000, “Traffic,” a best-picture nominee, “Contagion” follows the converging story lines of characters played by Gwyneth Paltrow, Matt Damon, Kate Winslet, Laurence Fishburne, Elliott Gould,Jude Law, Marion Cotillard, Jennifer Ehle and others, as they fight or fall victim to one of the few problems we have not faced (so far) this year: a deadly flu pandemic.

With its debut at the Venice film festival, which begins on Aug. 31, “Contagion” will join Roman Polanski’s “Carnage,” about intense personal conflict, and George Clooney’s “Ides of March,” about the ugly side of politics, in opening a season that will test the willingness of viewers to take on added anxiety.

Insofar as movies react to the national mood, they tend to go against prevailing trends. The most recent heyday in the United States for calamity films appears to have been the late 1990s, before the terror attacks and a series of wars took their toll. Pictures like “Armageddon,” “Deep Impact,” “Volcano,” “Twister,” “Dante’s Peak” and the disease thriller “Outbreak” all belonged to that somewhat rosier era.

No other major studio movie scheduled for release between now and the year’s end appears to match the insistence of “Contagion” on facing something terrible — in this case, the death of millions by disease — without the edge of fantasy that made recent apocalyptic films like “Rise of the Planet of the Apes,” “The Book of Eli” or “2012” perhaps less threatening.

For Warner Brothers, the film is not an enormous financial risk: The production budget is less than $60 million. But success means getting the audience to worry a little more at an already worrisome time.

“Today, there’s so much unrelenting bad news,” said Peter Sealey, a marketing consultant who was once at Columbia Pictures, “I don’t think people are ready to engage in more destruction and mayhem.”

Michael Shamberg, who, with his business partner, Stacey Sher, is among the producers of “Contagion,” said, “Hopefully, you can sell a lot of tickets if you find a fresh way to scare people.” Fright, he contends, draws an audience in good years and bad.

Mr. Shamberg and Ms. Sher were producers of Mr. Soderbergh’s “Erin Brockovich”(2000), which was also nominated for a best-picture Oscar and managed to turn a legal fight over chromium contamination into a story of romance and triumph for its star, Julia Roberts.

Now the filmmakers and Warner are presenting an A-list cast and a deeply realistic scenario of infection and death, with cooperation from the Centers for Disease Control and Prevention, as both a serious festival film and a broadly commercial thriller that is starting to get attention in places that usually ignore the likes of Mr. Soderbergh and Ms. Winslet.

“I’ve been covering it,” said Brad Miska, an owner of the horror-focused Web site Bloody-disgusting.com, which more typically follows pictures like the “Saw” series or the forthcoming “Final Destination 5.”

Mr. Miska, who spoke by telephone last week, said some of his readers initially gave him “the stink-eye” when he began posting items about news like Ms. Paltrow’s joining the “Contagion” cast. But, he said, some horror-attuned friends recently saw a screening of the film and assured him that it was “really, really dark and really, really scary.”

Sue Kroll, president for movie marketing at Warner, said the studio was not specifically seeking horror fans but would advertise to a wide audience. Over the next week or two, that means expanding the scare factor with bus posters and billboards that will feature, among other things, a gasping, bug-eyed Ms. Paltrow beneath a legend that warns potential moviegoers to steer clear of one another. “Don’t talk to anyone,” the posters say. “Don’t touch anyone.”

Martin Kaplan, the director of the Norman Lear Center for the study of entertainment and society at the University of Southern California, points out that cold war audiences were sometimes happy to “marinate in their fears” with films like “On the Beach” and “Fail-Safe.” Also, he said, viewers may be attracted to the hope, heroism and survival advice that will be part of the package in “Contagion.”

Participant Media, an issues-oriented film company that is financed by the entrepreneur Jeff Skoll and is one of the film’s backers, has already begun a social action campaign that may help viewers cope with a viral onslaught of the kind that, in some places, will arrive on giant Imax screens. On the TakePart.com Web site Participant and its allies, under a trailer for the film, are advising to stockpile bottled water, while offering a link to advice on“how to sneeze properly.”

Eventually, Participant expects to use Web videos and other tools to acquaint viewers with real-life virus hunters of the kind who are portrayed in the film: “part detective, part scientist, part daredevil,” says Kathy Jones, an executive vice-president for marketing at the company.

Mr. Shamberg said that Dr. Larry Brilliant, an international public health expert who is now president of the Skoll Global Threats Fund, was the first of a group of scientific advisers for the film. That number grew to at least a dozen while Scott Z. Burns (a producer of the global-warming documentary “An Inconvenient Truth”) was working on the script, and Mr. Soderbergh and his crew were turning it into a movie.

“I’m happy if we’re getting the scare crowd,” said Mr. Shamberg, who said the main impulse behind the film had always been to entertain. But, he added, “we want people to understand what the word pandemic really means.”