It would have to be the worst nightmare of a train passenger, not to mention the poor cow.
French media reported on Thursday that a train in northern region of Normandy lost control of the brakes after crashing into a cow on the tracks.
"After hitting a cow, a train lost its capacity to stop and ran adrift," said the Sud-Rail union.
Rail operator SNCF refused to comment until an investigation had been carried out, but confirmed that an incident occurred at 8am on Tuesday near the station of Ferqueux.
For the next 19 kilometres, the train was a runaway on what was thankfully a track that doesn't see a lot of traffic.
It remains unknown exactly what speed the train was travelling at, but by the time it reached an upwards slope, the driver managed to jump out and wedge the wheels so it wouldn't roll backwards again, reported Le Parisien.
The fate of the cow remains unknown.
The incident marks the second time a TER regional train has made headlines this week.
On Wednesday, a train in western France collided with a truck, injuring 15 people. It remains unknown why the truck was on the tracks, but an investigation has been launched.