set (something) over (something)
1. To place or rest something above or on top of something else. I set the picture over the fireplace on the mantelpiece. I always just set a book or coaster over the stain on the coffee table.
2. To establish a story, play, film, etc., as occurring over the some span of time or duration of something. Often used in passive constructions. The author set the majority of the story over the months leading up to the murder trial. The entire film is set over just a few hours, unfolding nearly in real time.
set something over something
to place something in a position above something else. Toby set the plate over the hole in the tablecloth. Please place the kettle over the fire.