The Moral: those who are unsure of their place in the scheme of
things are dangerous. The dualities:
A (1): Random is bewildered and desperate (2) the Grebulons on Rupert are unsure of where they stand in regard to everything. (And both commit destructive acts.) B (1): A spacecraft lands in Central Park (2) Another one lands shortly after (-headline: "'This One's Pink'".) C (1): On entering Stavro Mueller's 'Beta', Ford Prefect says (of Arthur), "It's OK, he's with me." (2) Arthur shortly thereafter says "If I'm here, we're safe." D(1) & (2): Arthur hears his name shouted 'in stereo'; there are two Trillians present. E(2): The Earth is destroyed, with Prostetnic Vogon Jeltz looking on.- Just as at the beginning of the series, (1) so at the end.
And there is reference to the right brackets (that close out a section
of code, by canceling the effect of a previous left bracket) in programming;
and the bird had resolved itself out of existence too.