Months after the zombie attack, B has become a revitalised: an undead creature who can reason, unlike the majority of mindless, vicious zombies. But, held prisoner in an underground complex, B and a group of revitalised teens known as the zom-heads are under constant guard, observed by a team of scientists and soldiers. When B refuses to co-operate, they are all denied brains as a punishment, the essential ingredient for keeping their minds rational. Can they survive their underground prison?