The rules about not being able to change time weren't set in stone, they were more like guidelines; after all, how much must Sara Lance and the other Legends have changed throughout history just by bloody being there?

At least, that was what Constantine told himself the day he prevented Desmond from going to hell; he'd fixed something that had been haunting him for ages.

Yet as all the possible timelines crowd in on his head, as he sees a new memorial photo in the Time Bureau every five minutes and Zari the cat looks at him with those reproachful feline eyes of hers, Constantine realised that Ava and the Time Bureau had their rules for a reason.