It's a scary thought, but imagine enjoying a school trip, only to go back to the coach at the end of the day to find it's already gone!
Well, that's what happened to a year seven pupil from Primrose High School in Leeds, who was left behind at a theme park miles away from home.
The boy was on an end of year reward trip to Lightwater Valley in North Yorkshire.
Thankfully, teachers noticed he was missing within minutes, and went back.
They immediately got in touch with staff at the theme park, who looked after the boy until the coach returned.
Afterwards, the school said it had carried out "a thorough investigation" into what happened.