This is killing me. I'm writing in the past tense (third person omniscient). A few times, I've found myself jumping back and telling about something that had happened before the time in the storyline. I have four scenes which are presented by jumping back from the main story line. "Oh, by the way, this had happened." Two of them are unavoidable: the story does not start with the characrters' early childhoods. Two others are within the time frame of the main story. It is these two that bother me: they are essential to the plot, but to me it is obvious that by inserting them in someting else I am saving on developing them on their own. They come out somewhat shorter with only the essential information and a few emotional touches. Brief sketches instead of fully developed illustrations which create the right impression. Are there any examples in accepted literature where this has been done with success? Or is there a rule that says "this is almost always bad." Getting the tenses right is a separate story which doesn't really belong in this thread.