▁though ▁no ▁dates ▁are ▁given . ▁Hum ans ▁have ▁expl ored ▁many ▁world s ▁in ▁a ▁number ▁of ▁different ▁galaxies . ▁Their ▁quest ▁is ▁for ▁knowledge ▁and ▁to ▁be ▁helpful : ▁there ▁is ▁a ▁strict ▁rule ▁against ▁' inter ference '. ▁ ▁The ▁narr ator , ▁Mary , ▁is ▁a ▁special ist ▁in ▁' communic ation ' ▁- ▁a ▁kind ▁of ▁tele path y . ▁She ▁oper ates ▁in ▁a ▁society ▁where ▁women ▁are ▁just ▁as ▁likely ▁as ▁men ▁to ▁be ▁leaders , ▁though ▁she ▁herself ▁pre fers ▁not ▁to ▁lead . ▁They ▁also ▁do ▁pretty ▁much ▁as ▁they ▁please ▁as ▁regards ▁sex ▁and ▁reprodu ction : ▁ ▁Vi ola ▁is ▁a ▁ha p lo id ▁human , ▁conce ived ▁as ▁a ▁result ▁of ▁sexual ▁interaction ▁with ▁a ▁Mart ian ▁- ▁Mart ians ▁being ▁herm aph rod ite . ▁A riel ▁is ▁an ▁al ien ▁creature ▁that ▁could ▁be ▁seen ▁either ▁as ▁a ▁par as ite ▁or ▁a ▁kind ▁of ▁child . ▁ ▁There ▁are ▁no ▁space - opera ▁thr ills ▁and ▁f ights : ▁rather ▁there ▁are ▁a ▁number ▁of ▁different ▁world s ▁with ▁interesting ▁bi ologies . ▁In ▁one ▁case ▁there ▁is ▁an ▁eth ical ▁problem ▁concerning ▁some ▁c ater p ill ars ▁and ▁but ter f lies , ▁both ▁intellig ent . ▁Att itudes ▁about ▁sex ▁and ▁about ▁al ien ▁cult ures ▁are ▁similar ▁to ▁those ▁of ▁the ▁New ▁W ave , ▁though ▁it ▁is ▁not ▁normally ▁class ed ▁as ▁part ▁of ▁it . ▁ ▁Public ation ▁history ▁▁ 1