Mattie waterfalled a bit of water into her rancid-tasting mouth. She gargled and spat and then went back inside. She could hear labored breathing. She'd heard it before and she knew what it meant. She had no desire to see another child die, and by her own hands. And she certainly had no desire to deal with the grief of her brother. What if that grief turned to anger? What if he decided to blame her? Sure, he'd known what he was doing when he fed the girl the pills but grief rarely made sense. All those feelings boiling inside... they could become dangerous. 

So when Alissa's quiet, weak breaths ceased, and when the orange firelight illuminated her peripheral vision, Mattie did not return to where she and Nick had been. No, it was too fresh for him. Seeing fire was too fresh for her. They were both hurting, and she was afraid that they would only hurt each other more. She wanted to be with him, of course, strangely. She wanted to give him every comforting word she could muster (that probably came to around two). 

But she didn't. 

She simply slunk into the darkness, as far back in the Wal-Mart as she could. She was somewhere in the freezer section when she decided that she was out of Nick's earshot. About an hour was spent crying. Another half hour was spent trying to sleep. Fifteen minutes went by where she talked to herself. And finally she managed to fall asleep.