People love a good horror film, but if you make it about masked lunatics killing teenagers, you limit your audience significantly, so it's best to scare them with the world as it is. One of the best ways to do that is to make a disease movie. That way, something as known and dependable as the back of your hand becomes the masked lunatic killing teenagers.
Contagion takes the loosely related ensemble approach to the disease genre, which, so far, is the only approach anyone has ever taken to the disease genre, so long as you don't count zombie films. There's just no other way to illustrate society reacting to the death of society than by introducing audiences to an entire society of characters and giving each one of them a good five-ten minutes each.
Let's start with the disease. It's a very bad one. It makes you have the flu at first, but then it goes a number of different ways. Maybe you'll have seizures. Maybe you'll just look really tired and die. At its worst, it takes over your brain and makes you kill yourself by running into traffic. Whichever way it chooses to take you out, your mouth foams at the end. That's the tell-tale sign you've been contaminated by Contagion.
Contagion first strikes China. Approximately five billion Chinese people are wiped out in less than a week, which is one billion more than normal. It comes to international attention when it kills a beautiful white woman. After that it kills Gwyneth Paltrow.
Before Gwyneth Paltrow dies, she has an affair with a dude we never see. This never materializes into anything important narratively, but it's important all the same because I will die before I let the bitch who cheated on me forget what she did.
Upon returning home, she says hello to her cuckolded husband, Fatt Damon, and drops dead. While Damon takes her to the hospital, his step-son also drops dead. He and his biological daughter, however, appear to be immune to the virus. This is because they do not possess cheater DNA.
So now that the thing which killed all those Chinese people is working on Americans, it's time for the government to get involved. They basically just go around putting masks on people and handing out a bunch of that weird hand sanitizer stuff. People are trying to find a cure, but it's difficult because there are still two whole acts left in the film.
One of the main government helpers is played by Kate Winslet. She informs us how dangerous the disease is, then catches it herself and drops dead. They end up burying her in a pauper's grave, just like they did with poor Mozart. Unlike the other bodies, she's buried naked because nudity is in Kate Winslet's contract. I don't recall hearing anyone complain.
There's another government lady played by Marion Cottagecheese. She goes to China to try an ascertain Contagion's origin. Instead, she gets kidnapped by Chinese children and forgotten about. By everyone. I even directed this film and would have forgotten if not for Wikipedia. I think the government saves her by giving her adorable kidnappers a placebo. And when she finds out about the placebo, she runs right out of the movie to warn them. Or she comically runs into a wall. I can't remember.
Meanwhile, there's a blogger named Perez Hilton who hates the government so much he pretends to be sick and pretends to take a cure and pretends to get better, creating a national surge for the product he was secretly paid to endorse and public distrust against Lawrence Fishburne for raising a naughty daughter. Fucking Perez Hilton. What an asshole.
While doing all this, he also takes many, many leisurely strolls in his bubble suit to gauge how much society has crumbled since the last ten minutes of the film. He doesn't actually talk to anyone, so you have to figure it out by how much trash is in the street.
But in other parts of the country, things look okay. Fatt Damon is stuck in Minneapolis because of quarantine. His house looks nice, though. And the electricity's still on. His daughter's iPhone still works. So for him, this is all an unexpected vacation from work. The people across the street from his get shot by looters, but they were jerks, so win-win! There are a couple scenes were he's scrounging for food, but from the looks of him the situation never gets too severe. His daughter's arc is also pretty lax: she's bored. So the Contagion plague really isn't as bad as those government stooges say. I mean, there's one part where he even goes to the mall.
Eventually a cure is found, and people start getting it based on their date of birth. People with same birthday as the president get it first. People with the same birthday as Jesus Christ get it second. People with the same birthday as Elvis get it third, and so on until the final handout day for people born the same day as Frankie Muniz.
The cure took a long time to come up with because it's so unconventional. After figuring out that the disease originated with bats, Elliott Gould discovers that by sniffing bat farts you can make yourself immune. So everyone gets a syringe filled with bat farts which they take by shoving up their nose and smelling directly onto their brains. It's not pleasant, but it's better than dying of Bat Fart Disease.
Once Fatt Damon's daughter gets the cure, she can finally see her boyfriend again. Damon sets up a faux prom for them in his living room then goes upstairs to finally cry over his lost wife while they begin the repopulation process downstairs.
And on that note, the film finally ends, and you're allowed to leave a theater filled with coughing assholes and enter a larger world of coughing assholes. They and their germs are out to get you. Go home. Quit your job. Isolate yourself. Don't trust anyone. You're welcome.