Two young boys in Pakistan literally 'power down' after the sun sets and can only move during the day.
13-year-old Shoaib Ahmed and 9-year-old Abdul Rasheed suffer from an affliction so peculiar that there are no other known cases of the condition anywhere in the world.
During the day the boys are perfectly healthy and can run around, play outside and do all the other things that children their age enjoy doing.
When the sun goes down however both of them become completely paralyzed and are totally unable to move or speak again until the first rays of sunshine stream in the next morning.
The pair have been under observation by doctors at a hospital in Islamabad where efforts have been underway to determine exactly what is causing their unique symptoms.
One theory - that the sunlight itself is keeping them going - has been ruled out as it was found that the boys are able to function just fine in a pitch black room in the middle of the day.
"We took this case as a challenge," said Professor Javed Akram.
"Our doctors are doing medical tests to determine why these kids remain active in the day but cannot open their eyes, why they cannot talk or eat when [the] sun goes down."