A video uploaded to the internet claims to show the moment a 'ghost train' rolled into a station in China.
In the clip, a train can be heard and seen pulling in, stopping, and departing without anyone getting on board. A few seconds later it leaves.
The whole time, the ground and railway tracks are clearly visible through the ghostly carriages.
"When the station's security [were] watching the surveillance cameras they noticed this," the caption on the video reads.
"My source said that in the 12 years he has worked there he has never seen anything like this before and hopes he never does again."
The clip has been viewed more than 105,000 times.
Eyebrow-raising theories offered by viewers include time travel, "invisible cloak" or "a train failing at being... holographically invisible".
More likely explanations are that it's a reflection in a window, a double exposure or perhaps computer-generated imagery.
The account, The Hidden Underbelly 2.0, regularly uploads videos of what it says are UFOs and unexplained phenomena. Recent videos include 'UFO caught using the sun's glare as camouflage' and 'Bizarre object imitating a cloud'.