Yes, you read that right.
You've got another think coming.
In THE SECRET HISTORY, I had a line that said, "He had another thing coming."
Sounds right, yes? Wrong.
My wonderful editor gave me a new wrinkle for my brain (is that actually backed up by science?) when she pointed out that the saying is actually "another think." Apparently the phrase came from the expression, "If that's what you think, you've got another think coming."
That makes sense to my ear, but "He had another think coming" looks terribly wrong to my eyes. It's also apparently an Americanism which means it probably shouldn't be in a book about the Byzantine Empire.
So I changed it, but now I feel a little smarter knowing the "real" phrase.