Horror story in just one sentence.

3 friends lived in a flat on the 100th floor.

One day when the lift was not working they decided to tell each other stories as they walked up the stairs.

The 1st one told a comic story till the 50th floor.

2nd one told an action story till the 99th floor.

And the 3rd one told a horror story in just one sentence.

“I forgot the flat keys in the car”.