Disaster Diaries: Zombies! - R. McGeddon

It's the end of term and Sam and Arty are anxiously awaiting the final bell. They barely pay attention when the bumbling science teacher causes an explosion and accidentally covers one of the pupils with a strange goo. Sam and Arty are sure it won't be serious - stuff like this happens all the time at their school. But then zombies (and bits of zombies) start turning up, desperate to munch on braaaaaaaiiiins! With a bunch of useless adults quickly getting themselves infected instead of sorting the situation out, Sam, Arty and their fearless friend Emmie have to take charge. If they can't find a cure, they'll be zombie breakfast ...