The explosions knock the wind out of Katniss and cause her to lose hearing in both of her ears. She knows that the Careers will be coming back to see what's become of their camp, but she can't stand. She crawls into some brush for cover just before Cato and the rest of the Careers come bounding through the woods and into the clearing. Cato is livid. He kills the boy from District 3 by snapping his neck and, at nightfall, the Careers head back into the woods to hunt. The next morning, Katniss has regained some of the hearing in her right ear, but believes the left one is damaged beyond repair. She makes her way back to the site of her and Rue's first meeting slightly disoriented, feeling blind on the left side of her body without any of the noises of the woods. Rue hasn't shown yet, so Katniss waits for her in a tree. The day passes and still no sign of Rue.
Katniss sets out after her and when she reaches the point of the third signal fire, she sees that Rue never made it back to light it. Something has gone wrong. Katniss searches for Rue, and when she hears the mockingjays singing Rue's song, she knows that Rue is nearby and has been singing recently. Katniss sings the song back to the birds and they respond. Then she hears Rue scream. Katniss, disregarding her own safety, yells Rue's name and sprints into a clearing. Rue, tangled in a net, says Katniss' name just before the spear enters Rue's body.
Cato has already expressed multiple times that he wants to be the one to kill Katniss. After the Careers' camp is destroyed and they discover that the person responsible for the blasts survived, we can be sure that Cato will suspect Katniss and pursue with even more violent and aggressive resolve.
Katniss, however, is confident and ready to take Cato on, saying that she's ready for the real Hunger Games to begin, which foreshadows battle between these two tributes.
While Cato's anger and Katniss' direct promise of a challenge to him add to the novel's tension, so does Katniss' loss of hearing. With her hunting senses dulled, she's now a much more vulnerable target.
When Katniss calls to Rue and races to save her, without any thought to her own safety, this recalls the moment when Katniss sacrificed herself for Prim, reinforcing just how strong is the bond between Katniss and Rue.
In this chapter, Katniss endures both loss and gain. Throughout, she's been fighting with Prim on her mind. Now she has Rue to fight for, too.