It’s Halloween—a time when we’re preoccupied with witches, ghouls, and other frightful creatures. But this year, no creature is generating as much buzz as the zombie. Zombies have inspired movies and TV shows, video games—even a bloody Pride and Prejudice takeoff. Could all this talk of the undead be foreshadowing a real-life zombie apocalypse? In fiction, yes. But not in real life. A Harvard ethnobotanist once found that a neurotoxin was the cause of several cases of zombie-like living deaths in Haiti. Oddly shaped proteins called prions have also been linked to brain diseases that vaguely resemble zombieism. In his novel The Zombie Autopsies, Dr. Steven Schlozman, a zombie enthusiast and professor of psychiatry at Harvard Medical School, imagined an infection scenario that turns normal human beings into flesh-craving monsters. Although a pandemic that creates zombie-like symptoms is theoretically possible, a real-life zombie apocalypse shouldn’t be high up on our list of worries.