Fellow speaker,
To get your audience interested in your story, it helps to have "set up lines" in your story. Set up lines in your story create a question in the audience's mind that they have to listen to later in the speech for an answer. For example, you could be telling a story, and suddenly have someone in the story say, "Wow! That was great advice you gave! It really changed things for me!" and then the audience would have to wait for later in the speech find out what the "great advice" was.
Setting 'em up,
Tim