Grendel- things to do an outline on :[?

In english we are supposed to make a whole outline on something in Grendel. it can be about binary opposition, themes, the astrology, etc. I just can't seem to narrow it down to something to make a whole outline on. She said that it shouldn't take things from the whole book, just a few chapters. Answers asap please? outline is due in an hour :] hooray for procrastination.