I'm writing a story about a university student who falls in love with a close friend of hers who has a girlfriend (groundbreaking, I know.) The whole theme of the piece is about how the high that love gives you is the same high that drugs give you, and the addiction that results from both. About two thirds of the way through, he leaves her for good, and practically disappears from her life. The protagonist then goes through a period of drug experimentation, and tries to fall for other boys to no avail. They all pale in comparison to the feeling that the original boy gives her. The closing scene is of the two finally meeting again, and although intense feelings remain, they go their separate ways, and the boy ends up engaged to another girl. The story is divided into two parts: 'before' he leaves, and an 'after,' which is when she begins to experiment and he is absent from her life entirely. My question is, how should I go about the part in which they are separate and absent from each other's lives? I've thought about omitting it entirely, but I feel it's integral to the theme, and integral to explaining why it doesn't really work out between them. What I have at the moment is an opening scene where the reader is launched straight into her new life. She has a boy chase her during this period, and I have a scene where she tries to fall for him but finds herself unable. I don't want to skip over it but I don't want to ramble on too long (like I'm doing with this post.) I also have a bunch of summary I could use. I know I shouldn't introduce characters late in the story, but how do I write about her new life without doing so? I could use summary, but it feels too skipped over, and I don't want to give the reader the impression that we're all just hanging out waiting for him to pop back up. I really want to dig in that feeling of missing someone so deeply while being immersed in a new life, and I really want to draw that parallel well between the high of drugs and love. Any tips or advice?