Excellent shot - well done . They don't fly slow - I know I've had plenty of them in my front room before.
Did you have a window open?  - in which case it was probably pursuing an insect drawn towards the light .

My visitors were due to a colony living in the loft space. The little 'uns seem to come out about this time of year and fall from the eaves. They then crawl back up the wall, but enter any open window on their way   

Unfortunately some of them get exhausted from the effort and I end up having to revive them with some honey in water before they get their strength back and I put them near the top of the wall by the opening to find their way back into the loft. 

They're fascinating creatures - I love them.

The only disturbing moment  I've had was when my mother in law came to visit for the first time at our new home (I was not very used to seeing them at that time ) and I caught sight of one just appearing over the back of the sofa right behind her -  lol.   I looked at the wife and she at me !

I wanted to point and shout -  BAT !         but I thought MiL might get the wrong idea

Fortunately MiL decided it was time to retire, and I rescued the poor little fella after she had left the room .

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html