One has to believe that these appalling things took place exactly as the author says they did.
There was, however, only one reason to do this appalling thing.
An appalling thing was taking place before his eyes.
I like to do appalling things to people who upset me.
The appalling thing is that none of us saw this coming until it was too late.
Assuming they survived whatever appalling thing was about to happen.
The world is not an easy place, and sometimes appalling things must be done to avoid an even greater evil.
What an appalling thing for a professional photographer to say.
I can hardly believe even now that this appalling thing has happened.
Shame was no small part of her emotions, it had been an appalling thing to say.