The new age of the zombie movie is here. Not so long ago, you couldn’t turn on a screen without tripping over a zombie TV show or movie. Thanks to the instant success of The Walking Dead, the mid-to-late 2000s and early 2010s offered a veritable feast of rotten flesh for genre fans. It wasn’t all good, exactly, but there was an abundance. Then the rot set in, and oversaturation turned the subgenre into a punchline, just as it had the vampire movie, and cheap cash-ins and increasingly unimaginative retreads meant zombies simply stopped being scary. Or profitable. And it...