The zombie filmography primarily consists of claustrophobic tales with small groups of individuals trying to survive among the undead. Their stories invariably pick up well after the initial apocalypse. You know the drill.
In contrast, World War Z - like the Max Brooks book this film is based on - grandly tackles the global zombie outbreak at ground zero and chronicles its spread as a geopolitical epic.
It's a very different approach, less a horror movie and more a disaster thriller. The highlight is director Marc Forster's rendering of tsunamis of flesh eaters as never seen on film before. That part is impressive but, alas, it is not sustained.
At the centre of the story is United Nations field agent, Gerry Lane (Brad Pitt), who is trying to trace the origin of the plague. The film starts with him and his family surviving a zombie onslaught in downtown Philadelphia. The undead arrive in an aggressive ant colony-like swarm . This opening resembles War of the Worlds, complete with a Spielbergian dangling of helpless children into unpredictable terror.
After the wife (Mireille Enos) and kids are whisked to safety on a military destroyer at sea, Lane - whose skill set resembles those of Man Vs Wild's Bear Grylls - flies to various parts of the world seeking clues about what they are battling. Even as global infrastructure fails, he manages to crisscross continents to piece together a defence against the pandemic.