So he wouldn’t tell me the plot, so I didn’t know much about HAL except that there would be an intelligent machine in this thing. But there was another little scene where... I described... I had an article... an interview so it's all written up somewhere. But... there was one point where we were actually in a... we went into a little theatre and there were some people that Stanley had gotten to... to look at this preview of... and the preview was a part of the light show. Remember the... that marvelous thing. And... oh and somewhere, and there was a picture in... and the... the artifact was a tetrahedron, before, it was a slab. So he was showing this crater on the moon and there was a tetrahedron, which was black. And, but it's a triangular base, it’s not like an Egyptian pyramid, which is a square base. A tetrahedron is this triangular base thing. And somebody... one of the consultants or whatever was saying: 'What is... what is that thing?' And Stanley said: 'That’s a tetrahedron.' And... and the visitor said: 'What shape is it?'  He’s looking at it. And Stanley realizes that ordinary people have never seen a tetrahedron and they don’t know what it is and they’re a little bit disturbed. And he scrapped it and made it into the... this is a... to me, this is a bizarre event because the idea of somebody not recognizing a tetrahedron is pretty alien, but Stanley regarded it as... oh, I don’t want anything in the movie that they don’t understand.