Only children can colonize the planet Prokaryon, genetically modified for a world whose chemistry kills unaltered adults. A colony of orphans struggles to survive, and finds the planet hides strange secrets.The Prokaryan landscape is ordered, as if by unseen gardeners, hidden "masters" no human has ever found. The weather behaves as though designed to meet the planet's needs. When fire threatens a forest, a rainstorm appears, only to dissipate when...