Not good. I'm glad you avoided what could have been a trip to hospitalWinning by just missing falling down stairs and possibly killing a cat in the process.
I just popped down to get a drink of water. One of the cats who has spent the summer sleeping in the grapevine pot on the veranda has now decide to move back inside and sleep on the top step.
I'd not turned the lights on so it was luck that i noticed the slightly darker shape.