A good way to intensify meaning in the conclusion of a speech is to use an example.
Giving the audience an example helps the audience remember the importance of what you are saying and can help intensify the meaning. While a long story might capture the audience's attention, it would be something that would serve better in another part of the speech. A conclusion should not include any new information and should simply summarize what you have already said. It may also call your audience to action.