Not sure if the “Z” means the last World War or if it stands for zombie. Either way, there’s a worldwide outbreak of undead and Brad Pitt is dispatched by the UN to solve the crisis. The plot is standard formula (there’s even a kid with asthma) and dotted with leaps of logic. The frantic fervor of the zombies is the only cool special effect. Throughout his worldwide quest, the action never loses momentum and borders on gripping.