Late one August night, almost 30 years ago, a mysterious flash of light bore down on a Marshall County deputy as he was patrolling the western edge of the county.
The light lasted only a few minutes, before Sheriff Deputy Val Johnson, who was driving along Minnesota Highway 220, lost consciousness of time.
A few minutes grew into half an hour - 40 minutes, before Johnson became aware of the night again, and when that happened, damage had been done to his eyes and his squad car.
The cause of the light has remained a mystery since August 1979. And it's been the subject of much speculation. Enough speculation to draw the occasional interest of publications and television producers, according to Ethel Thorlacius, the director of the Marshall County Historical Museum.
Today, Thorlacius said, producers from the History Channel will be visiting the museum, which houses the squad car Johnson was driving that night.
The car retains unusual damage, she said, from a broken headlight to a long dent in the hood, a hole in the windshield and an antenna bent at a 45-degree angle.
It's become the county "UFO car," though Thorlacius said there's no way to know what caused the damage.
"I believe that there was something outside that car that was responsible for the damage," Thorlacius said.
A UFO, a ball of lightning, St. Elmo's fire, all come up on Thorlacius' conjecture list.
"You would have to see the damages to understand how unusual they are," Thorlacius said. "It's, well, it's like something went right over it, rolled over it."
Maybe she'll never know how the damage occurred, but she will have many more opportunities to discuss it as interested parties come through to talk about it.
"I know there are a lot of people who believe that nothing really different happened," she said. "It's controversial, just like anything about the unknown."