"You don’t understand Granger," Draco leant forwards to catch her frantically windmilling arms and press them down into her lap, his voice gentle, "we never intended to come back. We -  I - accidentally triggered a rune circle designed to send someone back through their own time. This isn’t time travel as you know it. This is like time travel plus dimension hopping. There is no going back. There are no irrevocable changes, because there’s nothing to change - only time flowing on its new natural path,"