The "Ring" in 70 minutes

I am starting to prepare my talk on the Ring Cycle next month. I have about 70 minutes. How does one introduce total novices to this monumental work in such a short time? I did this last year also, and it seemed to work. Naturally, I left out a huge amount of material. But I couldn't end my talk without showing a video of "Leb wohl," possibly the most moving excerpt in all of Wagner. It seemed to me that the audience watched transfixed, so I suppose that was a good segment to show. Besides, this is the one that persuaded James Morris to sing Wagner, long before he became the reigning Wotan at the Met and elsewhere.