[A story of the "Hainish" series.] A volunteer group of humans and aliens embark on an exploratory mission to a distant planet where they will run environmental tests as preparation for colonization. One of the ship's crew of 10 is a human empath whose role as ship's Sensor is to detect any presence of intelligent life, but upon their arrival they find vast forests and open fields of grasses, without animals of any kind ... not even an insect. Unable to stand the irritatating emotional excreta of his fellow crewmates, the empath sets up an outpost to do a species count on the local flora, but when he fails to report in on the radio, the others suspect the native vegetation may not be as harmless as it seems. Locus Poll Award Nominee, Hugo Award Nominee