On a routine flight from Los Angeles to Paris, a renegade group of scientists has smuggled aboard a secret container holding a fellow scientist infected with a deadly genetically engineered virus which reanimates the dead. The virus is a variant of the virus malaria created by three scientists. They discovered and manufactured the virus with the intent of turning it into a biological weapon. Their goal was to produce soldiers who could continue fighting, even while mortally wounded. The virus is transmitted through bodily fluids. The infected have superhuman abilities, sprinting and leaping beyond human capabilities. The zombies become very durable, and a particular zombie survives despite being thrown into a plane's engine.
The 747 jumbo jet encounters massive thunderstorms, and the turbulence releases one of the scientists from the cargo hold. Two of the scientists go below to ascertain if the container has been damaged by the turbulence, and are also killed, starting a zombie outbreak. The uninfected passengers must fight for survival aboard the flight. No government will allow the infected airliner to land, leaving the survivors stranded in the sky with their ravenous tormentors. Billy, his wife Anna, Burrows, Frank, Paul, and Megan, a stewardess aboard the plane, are all that are left of the uninfected people. They must make their way to the cockpit and signal a fighter jet behind them that there are still living people aboard the 747 or the fighter will destroy them. After managing to get the MP5K from the dead guard, Burrows, Frank and Billy make their way from the tail of the plane to the cockpit, while the couple stay behind. Billy is bitten but manages to kill some of the undead passengers, while Anna comes to help Billy she gets bitten but kills the Undead by thrusting an umbrella into its mouth. After that they both get surrounded, Billy opens the emergency exit and most of the infected get sucked out.
Frank and Burrows make it to the cockpit where Frank kills the zombie copilot and pilot, and the two of them try to get the plane off autopilot and signal the fighter which fires at them. They are ultimately successful and waggle the plane's wings, alerting the fighter. The fighter pilot hits the abort key and the missile explodes away from the 747, but close enough to the plane to open a hole in the side. All the zombies are apparently sucked out. Frank and Burrows try to control the plane, but hit a mountain and crash land near Las Vegas, Nevada.
As Megan, Burrows, Paul, and Frank move toward the city, apparently some of the zombies also survived the crash, and they lurch toward the city as well.
What does the genetically engineered virus do?
Reanimates the dead