A former "Mission Impossible" operative SEAN AMBROSE has a plan to steal a deadly virus, let it loose in Australia, then make a fortune selling it's antidote.
Tom Cruise's mission is to get back the virus from Ambrose before it starts infecting Australia.
To do this he tracks down Ambrose's former girlfriend played by Thandie Newton. He convinces her to get back together with Ambrose so she can help Cruise get the virus. Ambrose is suspicious and sets her up, wearing a Tom Cruise mask, to discover what she is really up to.
Cruise breaks into the laboratory that is making the virus and destroys all but one injection. Ambrose is right behind him and captures him. He orders Thandie to pick up the injection which she does but instead of handing it to Ambrose, she injects herself with it. Ambrose can't kill her now since she has the only known virus left. She is a human petri dish and has 20 hours to live.
Cruise escapes and rushes to an island fortress that contains the anti-virus.
Ambrose lets Thandie loose in downtown Sydney. Once she starts reacting to the virus, she will start infecting everyone.
Cruise is caught by Ambrose's assistant Hugh Stamp and is brought to Ambrose. Ambrose guns Cruise down in front of everyone. Then Ambrose discovers that Cruise's finger is cut, the same way that Ambrose cut Hugh Stamp's finger earlier in the film.
He goes up to Cruise's dead body and rips off a mask and realizes he just killed Hugh Stamp. The fake Hugh grabs the anti virus and runs to the awaiting helicopter. Along the way, he removes his mask revealing that it is actually Cruise.
Cruise orders the helicopter to go get Thandie and jumps on a motorcycle to escape. A wild chase goes on for about 15 minutes ending with Cruise and Ambrose, one on one. They have a fist fight and Cruise does a "John Woo" type move and knocks Ambrose down, hitting his head on a rock, knocking him out.
The helicopter arrives with Ving and Thandie. Cruise hands Ving the anti-virus. Suddenly Ambrose wakes up and points a gun at Cruise. While he's talking a wind kicks up and blows away some dirt on the ground uncovering another handgun. Cruise kicks the ground using his foot as a sand wedge and up comes the gun, grabbed by Cruise and in a slow motion back flip twist (John Woo again) shoots and kills Ambrose for good.
Thandie is injected with the anti-virus and in the final scene, she and Cruise are embracing in a crowded park in downtown Sydney.
Spoiled by: The Movie Spoiler