Nobody knows how it happened: an indoor house cat which got lost on a family excursion managing, after two months and about 200 miles, to return to her hometown.
Even scientists are baffled by how Holly, a 4-year-old tortoiseshell who in early November became separated from Jacob and Bonnie Richter at an RV rally, appeared on New Year's Eve - staggering, weak and emaciated - in a back yard about a mile from the Richters' house.
"Are you sure it's the same cat?" wondered John Bradshaw, director of the Anthrozoology Institute at the University of Bristol in England. In other cases, he has suspected, "the cats are just strays, and people have got kind of a mental justification for expecting it to be the same cat."
But Holly not only had distinctive black-and-brown harlequin patterns on her fur, but also an implanted microchip to identify her.
"I really believe these stories, but they're just hard to explain," said Marc Bekoff, a behavioral ecologist at the University of Colorado.
"Maybe being street-smart, maybe reading animal cues, maybe being able to read cars. I have no data for this."
There is, in fact, little scientific dogma on cat navigation. Migratory animals like birds, turtles and insects have been studied more closely, and use magnetic fields, olfactory cues or orientation by the sun.
Cats navigate well around familiar landscapes, memorising locations by sight and smell, and easily figuring out shortcuts, Bradshaw said.