I realize it's bad form to do two chapters in one update, but sometimes there's really no choice.
By now, I'm sure your eyes have drifted to the page count at the top. Yes, Chapter 28 is a mere two pages in length, and Chapter 29 is just a page more than that. If you've forgotten, these are the large-print edition pages, so these two chapters together are scarcely over a thousand words. The chapters in the last third of the story get really short - yet another serial-like aspect of the story.
But enough talk about chapter lengths. The important part is that this is where Emmeline and David do the nasty. Aww, yeah.
Chapter 28 is an extremely terse description of a pairing ceremony, followed by the nasty-doing that we've been building towards for nearly a hundred pages. It's obvious that Harriet Parke is uncomfortable writing explicit sex scenes and/or concerned that her readers would be uncomfortable reading them. The way you handle this is with a fade-to-black - a scene that attempts to maintain heat while stopping just short of the squeamish parts. Here's what that looks like in Agenda 21:
We spent the evening of his new sleeping mat, twined around each other like vines on trees. Later, much later, we ate our nourishment cubes.
The following chapter is there mainly to give us a glimpse into our very dull protagonist's very dull post-coital bliss. However, it does hint at what's to come:
"I used to hear Mom and Dad talking about your mother...She was George's teacher. Father told me that. And some things I didn't understand. Things about laws changing...Laws about animals. Laws about who owned the farms. Laws about energy."
Oh, don't even try and tell me that you weren't missing the exposition.
(In honor of these very short chapters, this is a very short post. That's the real explanation - it has nothing to do with the fact that I don't care to dwell on the queasy sexuality that runs through these pages)