Ana (sarah Polley)

Ana (Sarah Polley), a nurse, finishes a long shift at her Milwaukee County hospital and returns to her peaceful suburban home. She and her waiting husband Louis (Justin Louis) make love and go to sleep, missing warnings beginning to trickle through the local media (Neville Edwards, Natalie Brown, Dan Duran, Georgia Craig and Liz West) concerning a mysterious and rapidly-spreading contagion which turns its infected hosts into reanimated flesh-eating ghouls.

The next morning they are awoken by their zombified neighbor, a young girl, who bites Louis in the throat. Ana locks the zombie out of the room, but despite her frantic efforts, Louis dies, immediately reanimates as a zombie, and chases Ana into the bathroom. Ana escapes out the window and flees from her now chaos-torn neighborhood in her car, before a failed hijacking attempt sends her crashing into a tree. The opening credits roll, showing the worldwide collapse of human civilization.

Ana meets Kenneth (Ving Rhames), a grim police sergeant traveling to Fort Pastor, a nearby US Army base. With the route to the base blocked by zombies, they and three others - jack-of-all-trades Michael (Jake Weber), petty criminal Andre (Mekhi Phifer) and his pregnant Russian wife Luda (Inna Korobkina)- break into the nearby Crossroads Shopping Mall. inside the mall a scuffle with a zombified mall security guard results in Luda getting a minor bite-wound and Kenneth getting a cut on his arm.

They confront three living security guards - C.J. (Michael Kelly), Bart (Michael Barry) and Terry (Kevin Zegers) - and give up their weapons in exchange for refuge. After the group secures the mall, they head up to the mall's roof to dispose of bodies and paint SOS signs. There, they "meet" another survivor, Andy (Bruce Bohne), who is stranded alone in his gun store, across the mall's zombie-infested parking lot.

The next day, a delivery truck arrives at the mall, carrying the driver Norma (Jayne Eastwood), jerkish Steve (Ty Burrell), working man Tucker (Boyd Banks), elderly Glen (R.D. Reid), trampy Monica (Kim Poirier), bitten Frank (Matt Frewer) and his teen daughter Nicole (Lindy Booth), and an anonymous (and severely-injured) obese woman (Ermes Blarasin). These newcomers report that Fort Pastor has been overrun by zombies and no help is coming. Shortly after, the obese woman dies, reanimates and is killed by Ana, who thrusts a metal fireplace poker into her eye. The group determines that bites are how the zombies multiply their numbers; after Ana and Michael argue about what to do with the rapidly-deteriorating Frank, the man is isolated in a store with guard Kenneth, allowing him "every single second" before expiring. Michael and Ana achieve an awkward reconciliation, which is interrupted by Kenneth's shotgun blast as he destroys Frank's reanimated body.

Though the mall provides many material