Snakes on a Plane
NOTE: This spoiler was sent in by Lulu.

The movie opens in Hawaii, with scenes of people surfing and hanging out on the beach and an extended scene of Sean Jones dirt biking home from the beach.  He stops and gets off near a bridge and as he's wandering around a badly beaten men falls from the bridge, hanging by his feet.  Sean tries to help him but the man tells him to run and hide.  Sean watches from the side of the bridge as three men surround and taunt the man.  One of them (who is identified by the dialogue as Eddie Kim) beats him to death with a baseball bat.  Sean runs and they see him and shoot after him, but miss. 

The movie then cuts to Sean in his apartment where he learns that Kim is a leader of a Los Angeles gang and the man he killed was an LA attorney who was trying to stop him.  As he watches, he hears a noise near his door and looks through the peephole to see that two of the men with Kim (plus a third man) are breaking the lock on his door.  Sean runs to his patio where he is grabbed by FBI agent Neville Flynn (Samuel L. Jackson), who tells him to do what he tells him to do and he'll live.  Flynn shoots two of the men as they break in and then he and Sean jump from the balcony and drive away. 

In an interrogation room, Flynn and his partner tries to convince Sean to fly to LA to testify against Kim but Sean is scared and doesn't want to miss his planned trip to Bali to surf.  Flynn leaves the room, telling Sean to think it over for a few minutes.

The scene then cuts to the airport, where we are introduced to a rapper (3Gs), his two bodyguards (Troy and Big Leroy), a rich girl (Mercedes) with a little dog (Mary-Kate), and a woman and her hypochondriac husband returning from their honeymoon.  On the plane are flight attendants Claire Miller, Grace, Ken (who acts like a stereotypical gay man), and Tiffany (who is sexily dressed).  The other attendants congratulate Claire, since this is her last flight before she quits to be a lawyer.  However, the pilot annoys her by calling her "honey" and "darling" and telling her that she will have to be the one to tell the first class passengers that they must travel in coach instead. 

The movie cuts to Sean and Flynn looking out on the plane, which is being searched by police with guard dogs.  To make sure that Sean is not killed, they will have first class all to themselves. 

The movie then cuts to a man watching the police inspect the plane; he calls Kim to tell him that Sean is on Pacific Flight 121.  Kim calls a man and tells him to spray pheromones on the leis handed out to passengers, so the snakes will be especially upset. 

The movie cuts to a man kick-boxing (Chen Leong?)- the man with him seems to know there will be snakes on the plane and tells him not to be a hero.  Because of this scene, I think he is one of Kim’s employees but he doesn’t act villainous at all for the rest of the movie and the point of him being on the plane is never explained. 

As the passengers board, we meet a Latin American woman (Maria) with a baby, two small boys traveling alone for the first time, a snotty British man who is upset at being bumped from first class, a young couple who are all over each other, and a fat, comically dressed women who drinks from a flask. 

The plane takes off and Mercedes moves over to sit and flirt with 3G, and Tiffany comes on very heavily to Sean. 

We see a timer counting down throughout these scenes and, after it hits zero, a stack of cardboard boxes snap open to reveal a cabinet full of snakes who slither around the baggage area and kill a cat. 

Meanwhile, the gropey couple moves to the bathroom to have sex, where they pull the smoke alarm out of the ceiling so they can smoke a joint.  Unfortunately, snakes slither through the hole where the smoke alarm was and bite the couple (one attaching to the woman's nipple).  Listening to the woman's screams outside, Grace and Ken comment that her boyfriend must be very good. 

In the other bathroom, a snake slithers into the toilet and bites down on the penis of a man using it.  He leaps away, cracks the back of his head on the mirror, and dies. 

A snake crawls out into the main cabin and begins climbing up the leg of the sleeping fat lady- she is having a sex dream and smiles as the snake crawls up her thigh and then her stomach. 

Another snake crawls out and gets into Mercedes purse- when Mary-Kate starts barking at it she assumes Mary-Kate wants a treat and reaches her hand in to get it.  Just as she is about to touch the snake, Troy shrieks because he has just lost his video game and she snatches her hand away in surprise.  She then reaches in and gets the treat without being bitten. 

Meanwhile, the snakes slithering around are causing important parts of the planes controls to dislodge and the plane starts sliding around as a result.  The pilot goes down below the floor to flip some switches; unfortunately, he is bitten while doing so. 

The co-pilot calls in Claire and Flynn and the three of them remove the body without encountering any snakes.  They assume the pilot has died of a heart attack. 

The co-pilot makes an announcement telling everyone to stay calm despite the turbulence and Claire goes back into the cabin to reassure the two little boys that everything will be alright.  However, as the turbulence continues the oxygen masks pop down- each one bringing with it a snake, which immediately begin to attack people. The younger of the little boys is bitten by a cobra.  The fat lady wakes up because of the screaming and the snake pops its head out of the top of her dress and bites her in the eye.  Another woman is bitten on the tongue by a snake hiding in her air-sickness bag, when she goes to throw-up.  Big Leroy is bitten on the ass.  Flynn's partner is bitten when he goes down to investigate the screams. 

The passengers panic and run, with disastrous results.  A man is killed when the fleeing crowd knocks him down and a woman accidentally steps on him, driving her high heel into his ear. 

Mercedes (carrying her dog) and Maria (carrying her baby) are knocked down and knocked out by the crowd.  Some people try to fight back against the snakes- the hypochondriac’s wife smacks one away with her water bottle and Ken explodes another in a microwave. 

The passengers gather in a cabin towards the head of the plane and Flynn comes down from first class to instruct everyone to build a barrier of luggage to stop the snakes from coming through.  Flynn goes to phone the FBI agent (Hank Harris) in charge of planning the security on the plane- Harris is stunned by what has happened and orders his team to find him the best snake expert possible, promising to call back when his team figures out what to do. 

Flynn orders Sean to stay in first class and wait for the phone call, telling him that if he gets killed helping out below this whole ordeal will have been for nothing. 

Meanwhile, Mercedes comes to and finds the cabin empty, except for snakes and dead bodies.  Fortunately, Chen Leong finds her and tells her to hop on his back and carries her and her dog to safety, breaking through the luggage barrier.  Grace hears a baby crying and breaks through another luggage barrier to go find it.  She sees Maria, who is just coming to and, panicked at the realization that her baby has fallen out of its sling, asks Grace to find it. Grace finds the baby and snatches it away just as a snake is about to strike it, but is bitten herself.  She and Maria make it safely to the cabin. 

The luggage barriers are rebuilt but, for some reason, they are only halfway up and snakes now start crawling over them. Flynn uses a fire-extinguisher to fight them off, then hands it to Ken when Claire comes to him, panicked, because she cannot find the two little boys and is worried they may also be behind the luggage barrier.  Flynn quickly finds them hiding in one of the plane’s kitchens. 

Maria has had experience dealing with snake bites back in her home-country and washes her mouth with olive oil, cuts the little boy’s bite open with the edge of her earring, and sucks the venom out of the wound, buying him a little time.  Back in LA, Harris picks up the areas “go-to for animal control”, Dr. Price, from his office.  Dr. Price deduces that the snakes have been drugged by pheromones improbably quickly but says he cannot figure out the anti-venom needed unless he knows what snakes they are and calls Flynn to ask him what type of snakes they are. 

The passengers are already fighting with each other but Flynn gives a speech and orders them to join together and go into the back of the plane to collect the dead snakes.  The process of gathering snakes is skipped- we just see Flynn holding a dead snake and trying unsuccessfully to describe it to Dr. Price.  Mercedes offers to photograph all the snakes on her Blackberry and e-mail it to the snake expert. 

The plane then starts lurching violently and Claire runs to the cockpit and finds that the copilot has also been bitten and died.  One of the snakes hisses at her menacingly from the floor and she attacks it with a fire axe, killing it just as Flynn comes in.  Claire and Flynn try to pull the plane out of a dive but (for pretty much no reason other than the added drama) it doesn’t pull up until they are just above the water. 

Miraculously, the pilot comes up from below the floor-boards, alive, and takes over the controls.  However, the damage has already been done- because of the tilting the food and drink carts have crashed through the luggage barriers bringing the snakes with them.

Against Flynn’s orders, Sean runs down from first class and bats the snakes away from people with a piece of luggage while yelling at them to climb the stairs to first class.  The crush of people causes the stair railings to fall off and some of the people fall to the snake-covered floor, while a couple of people already on the floor are killed by falling debris. 

At the same time, a massive boa constrictor (anaconda?) that was somehow in the light fixture crashes into the cabin.  It stares at Mercedes and the snotty British man, who throws it Mercedes’ dog to distract it.  Furious, Mercedes pushes him off the stairs and he is eaten by the boa constrictor. 

The hypochondriac and his wife also die- they are knocked out against the wall by the turbulence and awake to see snakes attacking them. 

Sean and the other passengers try to build a luggage barrier at the top of the stairs but realize it will not work since the snakes can climb up the railings of the stairwell.  Claire and Flynn come out of the cockpit (which is on the same level as first class) and Claire suggests inflating the lifeboat to block the stairwell, which does work.  Unfortunately, the passengers quickly realize that the air-conditioner is not working and, without any air coming in, they will soon be unable to breath. 

Frightened, 3G starts yelling and pushes Tiffany and Ken when they try to calm him down and pulls a gun on Flynn when he tries to restrain him.  Flynn points out that if he shoots the gun in the highly pressurized environment of the cabin it could potentially start a fire but 3G is too panicked to care.  Tony then tries to calm 3G down, reminding him of their childhood together; as 3G listens Flynn snatches the gun from him and points it at him.  3G sits down and Claire and Flynn go into the cockpit, where the captain tells them that the plane has tripped some switches which will cause the plane to crash if it uses too much power.  The only way to get the air-conditioning back on is to go down into the baggage hold and trip the switches. 

Flynn goes down into the baggage hold with a flamethrower Claire has constructed from hair-spray and a lighter.  Claire gives him directions on a walky-talky.  He finds the switch without being attacked but it is stuck.  Just as he is radioing Claire this, two snakes attack and he fries them with the flame thrower.  Then, he searches through the passengers’ luggage until he finds a knife and a harpoon gun. He uses the knife to move the switch and uses the harpoon gun to shoot a third snake.  (Grace dies sometime during this time, but I don’t remember exactly when.)

Back in LA, Dr. Price tells Harris that almost no hospitals in the US have the anti-venom for the snakes, since they are all non-US, and that he only knows of one man who would have access to so many poisonous snakes. 

Harris and his agents fly to the Nevada dessert where the man lives and, during a gunfight with Harris, the man is bitten by one of his own snakes. Harris refuses to give him anti-venom until he confesses to the plot and gives Harris a list of the snakes on board.  Dr. Price injects the anti-venom and he and Harris fly all the anti-venom back to LA. 

The plane is now very close to LA but is diving again.  When Claire and Flynn open the cabin, the captain falls out dead and, seeing several poisonous snakes swarming behind him, they quickly shut the door.  They ask the crew if anyone knows how to fly a plane and 3G says that Tony does.  First, however, they must get the snakes out of the cockpit. 

Everyone except Flynn and the flight attendants buckle into their seats and hold onto a rope stretched across the cabin and attached to the cockpit door.  Flynn shoots out a window, causing a vacuum to form which sucks the cabin door open and sucks the snakes out of it. 

As debris crash through the hole, it rapidly widens and grows stronger, sucking the lifeboat out of the stair-well and sucking the snakes out of the main cabin.  The flight attendants hold on to the edges of the seats with their hands as they are also pulled toward it. 

Flynn and Tony rush to the cockpit, where Tony admits to flight control that he’s only ever flown on a video game and that the game doesn’t teach you how to land.   Tony narrowly misses a building but successfully lands the plane. 

The passengers get off the plane on an inflatable slide.  Before he goes down, Sean pauses to thank Flynn and is promptly bitten on the chest by a snake.  Flynn shoots Sean in the chest twice and he falls down the slide, evidently dead.  Flynn slides down and peels open Sean’s shirt to reveal that he was wearing a bulletproof vest, to protect him from any assassination attempts on the plane. 

The little boy is given anti-venom by Dr. Price- who is able to figure out what snake bit him based on a drawing his older brother did of it. 

Flynn asks Claire to go to dinner with him.  Tiffany writes her number on Sean’s hand.  A girl in skimpy clothing rushes up to Ken and makes out with him- he is actually not gay, just flamboyant. 

Sean reminds Flynn that, when they first met, Flynn told him that he would have to follow his orders in order to live and Sean tells Flynn that now he, Flynn, has to follow his orders in order to really live. 

The movie ends with Sean teaching Flynn how to surf, presumably in Bali.