Once upon a time--
Scratch that, that's not right. Linear time does not exist for the Jenoine. There is now, which is the when of one. There is the past and there is the future, which is like saying there is the East and there is the West. There are what humans might call imaginary times, which is like saying there is the North and there is the South.
Let us say, once upon a place.
Once upon a place, and it was the only place, arrived humans.
The Jenoine thought them confusingly small creatures, capable of facing in only one direction. They tinkered with the humans, trying to introduce them to eternity. They had some outstanding successes, mostly with females, for some reason, and a number of cases which were, strictly speaking, failures, but intriguing in other ways.
The humans seemed ungrateful for the favor, as they spent most of their existences coming up with ways to remove one another from the realm of time entirely.
The Jenoine were unconcerned, until it became apparent that the humans had come up with a way to remove the Jenoine from time as well.
This, the Jenoine realized, would be a bother.