Nicely work by everyone.

The most common structural problem I noticed in unsuccessful scripts was a gap somewhere near the middle, to such an extent that there seemed to be two different stories. This audience had to expend a great deal of effort to weld the two plot lines together, which means they were taken out of the story.

I once heard a lecture by the composer Virgil Thomson, who regretted that he had once written an opera in two acts. The problem, according to Thomson, was that either the first act would be better than the second act, or it would be worse.

The advantage of a three-part structure is that it distracts the audience from the analytical, evaluative (i.e. out of the story) frame of mind — as long as the writer creates the momentum to keep them moving forward.