There was that thought again, and she growled, shaking her head as if she could flick the thought away like water flying from her hair. What does Samm think of me? What do I think of Samm? She told herself it didn’t matter, that they had more important things to worry about, but her heart didn’t seem to care. She told herself there was no point trying to decipher their relationship, because she didn’t even know what she wanted the relationship to be and therefore had no frame of reference. Her heart ignored all her reasoning. Her mind worked furiously on its own, thinking about who Samm was, about what he was, about where he came from and what he wanted and how Kira, the girl who kept risking his life, might fit into it. He talked about the world renewing itself, and all she could think about was being in that world together. It was the same talk she’d had with Marcus a hundred times, and she’d always yearned for something more. With Samm, though . . .

No. That’s not why I’m here. That’s not what I’m doing. Thinking about a future with Samm is a meaningless exercise when he’s just going to die in a year because of the Partial expiration date. Find the answers. Solve the problem. You don’t get a life until you make one worth living.

She rode on and watched the sun sink, watched the red sky turn pink, and then blue, and then the richest dark purple she’d ever seen. She watched the stars come out and shine until they seemed to light up the entire prairie. They camped in an open field, roasting rabbits Heron caught with a snare, and Kira closed her eyes and pretended that the world had never ended at all, that it was just beginning, that when she woke up in the morning the entire world would be like this spot: healed and whole, unscarred by human interference or Partial rebellion or any sign of civilization. She fell asleep and dreamed of darkness.

The next day they saw their first poisoned tree.

The wind was changing, the strong easterly winds off the Great Lakes slowly replaced, more and more each mile they traveled, by southern winds up from the Gulf of Mexico. It hadn’t gotten bad yet, but this twisted, stunted, stark-white tree was the first sign that the easy days were behind them. They were heading into the toxic wasteland.