As it feeds off human souls, who will stop the darkness from destroying mankind?

In James Herbert's The Dark, madness rages as the lights begin to fade and humanity is attacked by an ancient, unstoppable evil . . .

It came like a malignant shadow with seductive promises of power. And somewhere in the night . . . a small girl smiled as her mother burned . . . Asylum inmates slaughtered their attendants . . . in slimy tunnels once-human creatures gathered.