Klaus Kristiansen’s father had mentioned, once, that during World War II a plane had crash-landed in one of the field of their farm, outside the town of Birkelse, near the northern tip of Denmark.

Decades later, Kristiansen remembered that comment when his son, Daniel, came home with an assignment to write about World War II, and he suggested that Daniel go look for it, as The Local reports.

It was meant to be a joke, but after father and son went to the field with a metal detector, they started finding pieces of plane. When they started finding human bones, they called the authorities.

Soon, local police, bomb disposal teams, and German diplomats were all standing in their field.

The plane they discovered was a Messerschmidt Bf 109, a commonly used model during the war. The unfortunate pilot still had documents and papers in his pockets.