Adv. 1. retroactively - after the fact; "he will get paid retroactively"
How to use retroactively in a sci-fi way?
The space-time police retroactively punished the criminals by traveling back in time and punishing them.
But it means after the fact with the effects being carried over, but it doesn't mean go back in time, is there a word for this, because it doesn't seem to fit the meaning I want to assign it.