ers " ▁to ▁the ▁people ▁of ▁ancient ▁Egypt ▁and ▁who ▁return ▁to ▁protect ▁the ▁Earth ▁from ▁a ▁war ▁between ▁al ien ▁races . ▁ ▁David ▁Wis n iew ski ' s ▁book ▁The ▁Secret ▁Know ledge ▁of ▁G rown - U ps " ▁mentions ▁in ▁passing ▁a ▁hang ar ▁where in ▁employees ▁of ▁the ▁United ▁States ▁Government ▁" stack ▁all ▁the ▁b anged - up ▁flying ▁sau cers ", ▁imp lying ▁that ▁the ▁existence ▁of ▁such ▁is ▁well - known , ▁but ▁that ▁the ▁Government ▁attempts ▁to ▁conce al ▁it . ▁A ▁series ▁of ▁short ▁nov els ▁known ▁as ▁the ▁Out ern et ▁series ▁has , ▁as ▁one ▁of ▁its ▁prem ises , ▁the ▁idea ▁that ▁Stone hen ge ▁was ▁originally ▁built ▁as ▁a ▁means ▁of ▁communication ▁with ▁extr ater rest ri als . ▁ ▁An ▁obsc ure ▁novel ▁by ▁André ▁N orton ▁called ▁Mer lin ' s ▁Mir ror ▁port ray s ▁the ▁w izard ▁Mer lin ▁as ▁a ▁servant ▁of ▁bene vol ent ▁" S ky ▁People " ▁who ▁seek ▁to ▁elev ate ▁human ity ▁and ▁th wart ▁the ▁" D ark ▁On es " ▁who ▁wish ▁to ▁keep ▁human ity ▁ignor ant . ▁N im ue ▁is ▁described ▁as ▁a ▁servant ▁of ▁the ▁Dark ▁On es , ▁sent ▁to ▁prevent ▁Mer lin ▁from ▁giving ▁human ity ▁a ▁leader ▁( Ar thur ) ▁who ▁would ▁bring ▁it ▁to ▁the ▁height s ▁of ▁knowledge . ▁The ▁Sky ▁People ▁are ▁once ▁imp lied ▁to ▁have ▁assumed ▁the ▁gu ises ▁of ▁already - wor