In New Jersey, a man stabbed himself 50 times and threw bits of his own intestines at police. They pepper-sprayed him, but he was not easily subdued.
He was, people started saying, acting like a zombie. And the whole discussion just kept growing, becoming a topic that the Internet couldn't seem to stop talking about.
The actual incidents are horrifying and, if how people are talking about them is any indication, fascinating. In an America where zombie imagery is used to peddle everything from tools and weapons to garden gnomes, they all but beg the comparison.
The federal agency that tracks diseases weighed in as well, insisting it had no evidence that any zombie-linked health crisis was unfolding.
The cases themselves are anything but funny. Each involved real people either suspected of committing unspeakable acts or having those acts visited upon them for reasons that have yet to be figured out. Maybe it's nothing new, either; people do horrible things to each other on a daily basis.
But what, then, made search terms like "zombie apocalypse" trend day after day last week in multiple corners of the Internet, fueled by discussions and postings that were often framed as humor?
"They've heard of these zombie movies, and they make a joke about it," says Lou Manza, a psychology professor at Lebanon Valley College in Pennsylvania, who learned about the whole thing at the breakfast table when his 18-year-old son quipped that a "zombie apocalypse" was imminent.
Symbolic of both infection and evil, zombies are terrifying in a way that other horror-movie iconography isn't, says Elizabeth Bird, an anthropologist at the University of South Florida.
Zombies, after all, look like us, but they're some baser form of us -- slowly rotting, intent on "surviving" and creating more of their kind, but with no emotional core, no conscience, no limits.
"Vampires have kind of a romantic appeal, but zombies are doomed," Bird says.
The Centers for Disease Control got in on the zombie action last year, using the "apocalypse" as the teaser for its emergency preparedness blog. It worked, attracting younger people who might not otherwise have read the agency's guidance on planning evacuation routes and storing water and food.
On Friday, a different message emerged. Chatter had become so rampant that CDC spokesman David Daigle sent an email to the Huffington Post: "CDC does not know of a virus or condition that would reanimate the dead," he wrote, adding: "(or one that would present zombie-like symptoms.)"