There was supposed to be a lot of the late Terry Pratchett in Good Omens 3, the finale to Amazon's successful apocalyptic series based on the 1990 novel Pratchett co-authored with Neil Gaiman. There's not, though. And that's part of the reason why it's such a huge, unsatisfying mess. First of all, some backstory. There is, of course, only one source novel in the Good Omens canon. It was adapted in its entirety by Gaiman into the first season of the show, back in 2019, to considerable success.