Some of Hollywood's most glittering triumphs have been snatched from the slavering jaws of defeat. Gone With The Wind was shot by three different directors and suffered numerous delays, yet the sweeping 1939 romance reigned supreme at the Oscars with eight statuettes including Best Picture and Best Director. Joseph L Manciewicz's 1963 epic Cleopatra was beset with similar problems, almost bankrupting studio Twentieth Century Fox when the budget ballooned from two million to 44 million dollars. Lead stars Elizabeth Taylor and Richard Burton began a very public affair, which incurred the moral indignation of audiences, yet the dazzling historical drama still garnered four Oscars.

Now comes Brad Pitt's post-apocalyptic zombie action horror, which has been plagued by rumours of on-set traumas and was delayed by six months to allow filmmakers to completely rewrite and reshoot the final showdown. If poisonous word of mouth could slay a picture before it has even screened, World War Z would be as lifeless as the hordes of computer-generated undead that cram every frame of Marc Forster's ill-fated film. From this mire though, Forster and three screenwriters have bolted together a compelling survival thriller that is not the catastrophe the gossip-mongers predicted - but also not as slick and suspenseful as cast and crew would have wished.

Gerry Lane (Pitt) is a retired United Nations investigator, who devotes his time to his wife Karin (Mireille Enos) and daughters Constance (Sterling Jerins) and Rachel (Abigail Hargrove). During a drive through Philadelphia, the Lanes witness the spread of a disease which transforms men, women and children into merciless predators with a single bite.

Gerry's old boss at the UN, Thierry Umutoni (Fana Mokoena), guarantees Karin, Constance and Rachel passage on an aircraft carrier if Gerry will agree to travel behind enemy lines to discover the source of the outbreak. The search moves from a military base in South Korea to Jerusalem and finally to a World Health Organisation compound in Wales where Gerry and an Israeli soldier (Daniella Kertesz) join four doctors (Peter Capaldi, Pierfrancesco Favino, Ruth Negga, Moritz Bleibtreu) in the frantic race against time for a cure.

World War Z boasts a cracking opening 60 minutes, directed at breakneck speed by Forster, who captures the pandemonium as the infected swarm like rabid animals. The dramatic momentum slows noticeably in the rewritten final act that feels out of kilter with the rest of the film but does at least permit close-ups of the infected.

Pitt maintains beatific calm in the eye of a pyrotechnic-laden storm, which sacrifices scenes with Karin and the girls in favour of thrills and spills - though not blood spills. There is a conspicuous lack of gore to ensure the film achieves a 15 certificate. Heaven forbid the leading man should risk being torn limb from gym-toned limb by the zombies.