The planet called Dendra seemed too good to be true: one vast forest world, marvelous climate, few dangerous beasts, a balanced hospitable ecology -- all should have speed out a good place for a human colony. But the original survey team had registered doubts, listed it as borderline without further explanation. Nevertheless the politicians had okayed it, and a colony had been panded there ... and 150 Earth years had passed without anyone hearing from it. Not the recontact vessel Daedalus was coming to check up -- and they found the climate as marvelous as before, the forest green and friendly, and the colony an inexplicable disaster. There was a biological and psychological puzzle that had to be solved for the sake of all human world -- and for the drew of the Daedalus, it was either crack it or crack up!