AgroupofaliensarriveonEarthaspartofanadvanceinvasionforce.Theirmissionistokidnapasmallsampleofhumansandrunthemthroughaseriesofrigorousteststodetermineiftheywouldmakesuitableslaves.Harper,oneofthealienexperimenters,hasbecemefrustratedwithherplanetsendlesscycleofconquestandexterminationandbeginstofeelsomesympathyforherhumancaptives.Whiletheprisonersseeaglimmerofhopeinthecompassionatealien,willitbeanyuseinstoppingtheenormousattackfleetjustafewdaysfromEarth?