This... Was nearly much more technical. I went full on Star Trek technobabble in this scene regarding a whole bunch of things about the spell and the energy and the yadda yadda yadda.
Then I thought "this spell is already confusing people", and "all that's really important at the moment is the ambient magic getting used up, and whether the spell has any affect on the world around them."
And then I thought about how moonlight and tidal waves would work if we had multiple moons, for my mind tends to wander like that, but it got back to sorting out how to edit this down to just relevant technobabble soon enough.
As for what Tedd is referring to in that last panel, it's actually very possible to logically deduce, and here's a question one can consider to help with that: If Sarah's spell creates an accurate simulation of a time stop inside of her mind, what would it logically have to do first?