“We can’t tell you,” said Kira. I can’t even tell you who I’m with. “We’re looking for something, and I wish I could tell you more, but . . .” She paused, not certain what to say, and eventually just said, “Over.”

They waited, but there was no response.

“Passing atmospheric conditions,” said Afa. “Our reception might have been temporarily boosted or broken by clouds or storms or virga.”

“I still trust you,” said Samm. “If you think this is the way to go, I’ll follow you.”

Kira looked at him, long and hard, wondering what he saw in her that she didn’t. Eventually she gave up, shaking her head. “What about the Failsafe?”

“What about it?” asked Samm.

“We don’t know what it is, but the word means something that can’t go wrong—or something designed to jump in and fix things when they do. What if the Failsafe can solve all our problems, and all we have to do is find it and activate it?” She thought about Graeme Chamberlain, the member of the Trust who’d worked on the Failsafe and then killed himself as soon as he was done. She shivered despite the heat. “What if it’s something horrible, and right when we think we’ve fixed everything, the Failsafe jumps out and screws it all up again? We don’t know what it is. It could be anything.”

“How do you know it even matters?” asked Heron.

“Because it has to,” said Kira. “The Trust had some kind of plan. The cure for the human disease is in the Partial pheromones, plus there’s me, a Partial something-or-other living in a human settlement. None of this is by accident, and we have to figure out what it all means.” She paused. “We have to. It’s the same old argument I used to have with Mkele: the present or the future. Sometimes you have to put the present through hell to get the future you want.” She held the radio to her mouth. “We’re going on,” she said simply. “Over.”

CHAPTER TWENTY-ONE