When Klaus Kristiansen tried to bring his son's history homework to life, he probably wasn't expecting the boy to unearth a buried World War Two warplane.
Or for excited TV crews, forensic police and explosives experts to descend on his family's farm in Birkelse, Denmark.
But that's exactly what happened when 14-year-old Daniel Rom Kristiansen found the remains of a German Messerschmitt plane, and its pilot, in an unremarkable field.
According to Mr Kristiansen, his grandfather once told him that a plane had crashed there in November 1944.
He told Danish news station DR P4 Nordjylland: "When my son Daniel was recently given homework about World War Two, I jokingly told him to go out and find the plane that is supposed to have crashed out in the field."
Father and son joined forces with a metal detector, but never expected to find anything.
Mr Kristiansen, an agricultural worker, believed the wreckage had been removed years before.
But then, a telltale beeping on a patch of boggy ground.
The pair began digging, but realised they needed to go deeper.
They borrowed an excavator from a neighbour, and around four to six metres down, the plane's carcass began to reveal itself.
Their haul included an engine from the Bf 109 Messerschmitt plane, Luftwaffe munitions, and the bones of a crew member who died in the crash.
"In the first moment it was not a plane," Mr Kristiansen told the BBC. "It was maybe 2,000 - 5,000 pieces of a plane. And we found a motor... then suddenly we found parts of bones, and parts from [the pilot's] clothes.
"And then we found some personal things - books, a wallet with money... Either it was a little Bible or it was Mein Kampf - a book in his pocket. We didn't touch it, we just put it in some bags. A museum is now taking care of it. I think there's a lot of information in those papers."
Realising they had found something extraordinary, the farmer contacted World War Two historians and the Danish authorities.
Mr Kristiansen said the field was being used "for grass, or cattle".
His family has worked on the land where the plane was concealed for decades, oblivious to its secrets. He himself has lived there for 40 years.
"We had never seen anything on the surface," he says simply. "Not a single bit of metal.
"He was telling a lot of stories, my grandfather. Some of them were not true, and some of them were true - but this one was true. Maybe I should have listened to him a bit more when he was alive!"
North Jutland Police have now closed the crash site for investigation.
As ammunition was found with the plane, bomb disposal experts are on hand to remove it safely.
Forensic police are working to recover the dead airman's remains, and hope to identify him in due course.
"Probably there is a pilot who will be buried now in Germany," Mr Kristiansen says. "I would hope so."
As for Daniel... he has handed in his history homework, but hopes to update it when the details of the stricken plane - and the man who fell with it - come to light at last.