What had seemed to be her death was all a horrible mistake!

To turn back with the whole party would be a horrible mistake.

What you are saying sounds to me like the most horrible mistake a man could fall into.

This is not a rare case of the system making a horrible mistake.

What a horrible mistake she had made of her life!

There's been a horrible mistake, and we're so sorry, but what could we do?

Why did something sound like a great idea one moment and a horrible mistake the next?

It should have no other effect than to correct a horrible mistake of man and nature.

I suddenly felt like a kid who has made a horrible mistake at a party and doesn't know how to cover it up.

He said that the Council had made a horrible mistake because they?