OK, a word or warning. This is the chapter that caused me to lose one of my editors, so it's not a 'light' chapter. This is a significant transitional chapter, where instead of secondary characters getting killed, a primary character does. In order to highlight the significance, the death is more visceral (violent and more descriptive) than the others have been (which are largely emotional). In either case, it's sure to upset more than a few readers.
On a positive note, I'm sure many people will enjoy a bit more 'action' again, but... The point is, this is where the story takes a much darker turn, and my editor's reaction to it is what finally alerted me to the fact that the story had become so dark and brooding while I wasn't looking.
Up until now, the threat of disease has been overshadowing the group, and has begun to affect those marginally connected to them (Frank, Ma), but here it hits home, and does so fairly hard. It also does so by pointing out a different threat, not by disease or by an organized gang of survivalists, but by... well, you'll see.
However, the violence is short, with most of the chapter consisting of everyone talking about it afterwards, but for those uncomfortable with death it may be problematic. Since the violence is so short, it doesn't make much sense skipping it (the death will be as depressing reading the act as it will be reading the discussion). However, aside from the approaching sense of helplessness, this is probably the worst chapter before the concluding ones (chapter 23-25 will be released at the same time, since the whole story becomes a bit overwhelming at that point and I thought it was better to read it all at once, rather than worrying about it for several more weeks).
Anyway, I'll be glad to hear your thoughts on the matter.
P.S. Just a final note, if anyone finds the story's tone too dark, I won't be offended if you have to quit reading it. The sequel is already in progress, and it isn't nearly as dark as this one is. The reasons why this one is, and has to be, should be obvious. Book 2 takes a completely different tack, based upon what happened here, though it once again takes a completely new approach to the PA genre.