We’ve been following Katniss a long ways. After the second plot point, most of the story is over and we can feel it. From the moment Peeta gets his medicine to the climax is another eighth-section of the book, from 6/8 to 7/8.
After the big showdown at the Cornucopia, some quiet moments happen. Katniss has taken an injury and Peeta is still healing, but we spend almost the first half of this section with just the two of them, talking, them trying to survive. There are more quiet moments here than there have been since the Games started, and with good reason. They are playing a different sort of Game, and we are being prepped for what is to come: a bloody showdown at the end. A semi-brief respite before it all goes down.
This section is punctuated by the death of Foxface, whose death was a total surprise. No fight, no warnings, just a cannon in the air. With only Cato left to fight, the Gamemakers start changing the Game again, luring them together. Katniss and Peeta (in full attack mode this late in the story) charge right on in, knowing they don’t have a choice.
We’ve been prepped for the showdown of Katniss against Cato for a while now, even Katniss herself mentions it while they are on the way. But of course, the Gamemakers have another surprise for them, which the characters discover right at the 87% mark (halfway between the second plot point and the end). Muttations.
There is no turning back. There is only a fight to the death. This is the home stretch. The climax is here.