What does Daniel 9:27 mean?

'He will make a strong agreement with many for one seven. In the middle of that seven, he will stop sacrifices and offerings. On the wing of abominations will come one who destroys, until the end that is decided is poured out on the destroyer.' Daniel 9:27 - Modern Text Bible

(Gabriel describes a final period of trouble, with a ruler who breaks a covenant and brings devastation, but whose end is certain.)